ARCHIVED - Chronic Diseases in Canada

 

Volume 30, no. 2, March 2010

Chronic Diseases in Canada

Chronic disease abstracts presented at the Canadian Society for Epidemiology and Biostatistics Student Conference, May 2009, Ottawa, Ontario

A. B. Abdeljelil (1,2); J. Moisan (1,2); J.-P. Grégoire (1,2)

Author References

  1. Faculté de Pharmacie, Université Laval, Québec
  2. Unité de recherche en santé des populations, Centre hospitalier affilié universitaire de Québec, Québec

Use of cardioprotective drugs in newly treated individuals with type 2 diabetes mellitus aged less than 65 years

Background: People with diabetes have greater risk of developing cardiovascular diseases than the general population. In addition to their anti-hyperglycaemic drug (AHD) therapy, individuals with type 2 diabetes mellitus should follow a comprehensive cardioprotective regimen (CCR) which should include antiplatelet and antihypertensive agents and a lipid-lowering drug. Purpose: 1) To determine the proportion of diabetics aged less than 65 years who initiated a CCR and 2) to identify the reasons for CCR initiation.

Study Design: A cohort study using data from the Régie de l'assurance maladie du Québec.

Methods: Our study included drug plan beneficiaries aged less than 65 years who had made an initial claim for an AHD between 1998-1-1 and 2002-12-31. Initiation of a CCR was defined as the first billing of at least one claim for an antiplatelet agent or a lipid-lowering drug or an antihypertensive agent in the year following the date of the first AHD prescription. Associated factors were identified using a multivariate logistic regression.

Results: Of the 16 455 drug plan beneficiaries included in the study, 2 493 (15.2%) initiated a CCR. The risk of initiating a CCR was higher among men, people living in rural areas, those with a history of cardiovascular disease, older patients and those who began their treatment in 2002.

Conclusions: In this population, the management of cardiovascular risk is suboptimal


G. Agha (1); J. M. Murabito (2); J. W. Lynch (1,3); M. Abrahamowicz (1); S. B. Harper (1); E. B. Loucks (1)

Author References

  1. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec
  2. Boston University and National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts, US
  3. School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia

Cumulative life course socioeconomic position and ankle-brachial index

Background: The biological mechanisms by which cumulative socioeconomic position (SEP) across the life course may influence cardiovascular diseases (CVD) are not well explored.

Purpose: To investigate whether cumulative SEP is associated with ankle-brachial index (ABI), a measure of subclinical CVD.
Study Design: Prospective analysis of 1 454 Framingham Heart Study Offspring Cohort participants.

Methods: Cumulative SEP was calculated by adding the scores for three measures of SEP: father’s education, own education and own occupation. ABI was dichotomized as low (≤ 1.1) and normal (> 1.1) due to increased risk for CVD events with values equal or less than 1.1. Logistic regression analyses evaluated the associations of SEP measures with ABI.

Results: Cumulative SEP was associated with low ABI in men after adjusting for age and CVD risk factors (odds ratio [OR] = 1.95, 95% confidence interval [CI]: 1.17 to 3.27), but not in women (OR = 0.87, 95% CI: 0.57 to 1.34). Own education not extending beyond high school was also associated with low ABI in men after full adjustment (OR = 3.58, 95% CI: 1.64 to 7.81).

Conclusions: Cumulative SEP is inversely associated with ABI in men with their own education contributing significantly to this association. Understanding how cumulative SEP influences subclinical CVD may inform the timing and method of intervention for CVD prevention.


B. Aljasir (1,2); Y. Chen (1)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Department of Preventive and Community Medicine-PHC, WR, National Guard Health Affairs, Western Region, Saudi Arabia

Prevalence of ischemic heart disease among adults who report migraine headache: an analysis of cross-sectional data from the Canadian Community Health Survey

Purpose: To determine whether the prevalence of ischemic heart disease among people who report migraine headaches suggests an association between the two conditions.

Methods: This cross-sectional study analyzed data from the 132 792 participants in the 2003 Canadian Community Health Survey who responded to questions about ischemic heart disease (angina or myocardial infarction) and migraine headache. Logistic regression was used for multivariate analysis.

Results: The adjusted odds ratio for ischemic heart disease among survey respondents who reported migraine headaches was 1.94 (95% confidence interval [CI]: 1.57 to 2.41) for men and 1.95 (95% CI: 1.60 to 2.37) for women, with an overall adjusted estimate of 1.89 (95% CI: 1.63 to 2.18). The higher probability of ischemic heart disease among respondents with migraines in comparison with those without migraines increased with age.

Conclusion: The prevalence of ischemic heart disease among Canadians who report migraine headache suggests an association between migraine headache and an increased risk of ischemic heart disease among men and women.


K. K. Anderson (1); R. Fuhrer (1); A. K. Malla (2)

Author References

  1. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec
  2. Department of Psychiatry, McGill University, Douglas Mental Health University Institute, Montréal, Quebec

Health services use and treatment delay for patients experiencing first episode psychosis: a mixed-methods study

Background: Patterns of service use surrounding first episode psychosis (FEP) are complex and likely contribute to delays in treatment initiation.

Purpose: To examine socio-demographic patterns of health services use for FEP and the impact of treatment delay and service disengagement.

Study Design: Mixed-methods multilevel triangulation design to examine health services use by patients with FEP at the individual, clinical and population levels.

Methods: At the individual level, semi-structured interviews will be conducted to describe the experiences of patients seeking treatment for FEP. At the clinical level, an ambispective cohort study will be done to examine socio-demographic predictors of health service contacts for patients from a first-episode psychosis program, and the impact on time to service withdrawal. At the population level, administrative data from several health and social service providers will be used to examine socio-demographic patterns in service use and treatment delay.

Results: Pending

Conclusion: Few Canadian studies have examined patterns of health services use by patients with FEP, and none have used a mixed methods design. Research is needed to identify the barriers patients face when seeking help for a psychotic episode so as to improve the provision of mental health services.


F. E. Aparicio-Ting (1,2); H. E. Bryant (1,3)

Author References

  1. Community Health Sciences, University of Calgary, Calgary, Alberta
  2. Population Health and Information, Alberta Cancer Board, Calgary, Alberta
  3. Canadian Partnership Against Cancer, Toronto, Ontario

Individual, social and environmental determinants of physical activity in an Alberta cohort

Background: Physical activity is protective for a number of major cancers, yet little is known about how psychological, social and environmental factors work together to impact physical activity behaviour.

Purpose: To identify multilevel determinants of physical activity in adult Albertans.

Study Design: A cross-sectional study examining baseline cohort data and data collection by questionnaire.

Methods: Baseline data from the Alberta Cohort Study: The Tomorrow Project (TTP) were analysed to compare cohort physical activity levels with recommendations made by the U.S. Department of Health and Human Services (HHS), Health Canada (HC) and the American Cancer Society (ACS) for health and cancer prevention. TTP participants completed a questionnaire regarding individual, social and environmental determinants. Data analyses included multivariate and multilevel modelling.

Results: Of the 4 350 participants, 30% (1 305) met recommendations set out by HC, ACS or HHS (the last being the most stringent). Age, gender, body weight, perceived health status, smoking status, social support, self-efficacy, attitudes, decisional balance, marital status, educational attainment, employment status and income were predictors of meeting recommendations. Multilevel modelling found that neighbourhood characteristics also play an important role.

Conclusion: Strategies to improve the physical activity behaviour of Albertans will need to consider a broad range of factors to be successful.


K. Barrick, E. Bradley, K. Ishmael

Author References

  1. Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario

An evaluability assessment of the Canadian Hearing Society’s Hearing Help Classes and the hearing aid workshop “Getting the Most out of Your Hearing Aids”

Background: The Canadian Hearing Society’s Hearing Care Counselling Program offers services, including classes and workshops, to adults aged 55 years plus with suspected or actual hearing loss. For instance, the Hearing Help Classes focus on topics such as the barriers related to hearing loss, and the hearing aid workshop consists of topics related to purchasing, maintaining and using hearing aids.

Purpose: To conduct an evaluability assessment and develop an evaluation plan for two services provided by the Canadian Hearing Society, Waterloo.

Study Design: Evaluability assessment

Methods: The current record-keeping practices, resources, goals and evaluation readiness of the services were examined through interviews (with both participants and the facilitator) and site observations.

Results: The evaluability assessment assisted with the development of a realistic evaluation plan for the program, which recommended conducting a concurrent process and outcome evaluation.

Conclusions: In addition to the proposed evaluation plan, recommendations for the services include the creation of a database to manage future process and outcome evaluation data and consultation with other stakeholder groups to discuss changes in record-keeping procedures.


L. Bayentin (1); S. El Adlouni (1); P. Gosselin (2); T. Ouarda (1); B. Doyon (2); F. Chebana (1); A. Smargiassi (4); M.-F. Sottile (3)

Author References

  1. L'Institut national de la recherche scientifique – Eau, Terre & Environnement (INRS-ETE), Université du Québec, Quebec
  2. Institut national de santé publique du Québec (INSPQ), Québec, Quebec
  3. Ouranos Consortium, Montréal, Quebec
  4. Direction de santé publique, Agence de la santé et des services sociaux de Montréal, Montréal, Quebec

Climate and morbidity in Québec: assessment of the effect of climate on ischemic heart diseases between 1989–2006

Background: In Québec, cardiovascular diseases cause 36% of all deaths. Studies have suggested an association between climate variables, especially temperature, and circulatory diseases.

Purpose: To investigate and quantify the magnitude of the effects of climatic variables on the daily rate of ischemic heart diseases (IHD) hospitalizations for each health region.

Study Design: Generalized additive model (GAM) with penalized B-splines.

Methods: A GAM model was used to fit the daily IHD hospitalization rates with climatic conditions, controlling for gender and trends in time and day. Optimal lag search and best model selection were performed using the generalized cross-validation (GCV) criterion.

Results: The risk of hospitalization is higher for men and varies with regions. Exposure to a continuous period of cold or hot temperatures is more harmful than just one isolated day of extreme weather.

Conclusions: None at this time.


I. A. Bielska (1,2); H. Ouellette-Kuntz (1,2,3,4); D. Hunter (1)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. South Eastern Ontario Community-University Research Alliance in Intellectual Disabilities, Kingston, Ontario
  3. Department of Psychiatry, Queen’s University, Kingston, Ontario
  4. Ongwanada, Kingston, Ontario

Prevalence of psychiatric and behavioural conditions in individuals with an intellectual disability: a systematic review

Background: Intellectual disabilities affect up to 3% of the Canadian population. Individuals with intellectual disabilities have higher rates of health problems, including mental illness and behavioural problems, compared with the general public. People with intellectual disabilities who have also been diagnosed with a psychiatric or behavioural condition are described as “dually diagnosed.” Research suggests that the prevalence of dual diagnoses ranges from 14 to 60% depending on the population studied and the diagnostic criteria used.

Purpose: To better estimate the prevalence of dual diagnosis of psychiatric and behavioural conditions in individuals with an intellectual disability.

Study Design: A systematic literature review.

Methods: A total of 15 677 articles published between 1980 and 2009 were identified in relevant bibliographic databases by screening the titles and abstracts.

Results and Conclusions: Pending. This project is currently in progress. Two reviewers will assess the selected full-text articles. These will be evaluated for quality based on the representativeness of the sample to the underlying population and the validity of the instruments used to measure psychopathology. Data from the full-text articles will be extracted. The results will be described and illustrated in a forest plot.


N. Bonsu (1); S. Johnson (2,3)

Author References

  1. Program in Gerontology, University of Regina, Regina, Saskatchewan
  2. Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan
  3. Saskatchewan Population Health and Evaluation Research Unit, Regina, Saskatchewan

Effects of inulin-based fibre supplementation on lipid and glucose profiles of individuals with type 2 diabetes mellitus

Background: Individuals who develop type 2 diabetes mellitus increase their risk of developing other health problems such as cardiovascular diseases. Consumption of soluble fibre has been shown to lower serum lipid and glucose concentrations. Inulin is a type of soluble fibre whose long-term effects on serum lipids and glucose in individuals with type 2 diabetes mellitus are inconclusive.

Purpose: To determine the long-term effects of inulin-based fibre supplementation on serum lipid and glucose levels in individuals with type 2 diabetes mellitus.

Study Design: Randomized Controlled Trial.

Methods: Forty volunteers, aged 50 years plus, were randomized to supplement with either an inulin-based fibre or a placebo for 12 weeks. A background questionnaire and a three-day dietary intake questionnaire were used to assess the characteristics of the participants and dietary intake with specific reference to total fibre intake, respectively. Dependent variables included total cholesterol, high-density lipoproteins, low-density lipoproteins, triglycerides, hemoglobin A1c and plasma glucose before and after the 12-week period. A 2x2 mixed model ANOVA will be used in analysis.

Results: Baseline data collection has been completed. Follow-up data collection is ongoing. Completion is expected in June 2009.

Conclusions: None at this time


K. Bradley (1); M. Speechley (1); J. Lobos (2); E. Polatajko-Lobos (3)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Private Consultant, email:zjlobos@rogers.com
  3. Faculty of Technology, School of Manufacturing Science, Fanshawe College, London, Ontario

How effectively do hip protectors reduce hip fracture incidence? A systematic review

Background: Nearly 24 000 Canadians sustain hip fractures each year, often with devastating consequences. The literature is mixed with respect to the effectiveness of hip protectors, and a case can be made that their true efficacy has not been adequately evaluated, particularly with energy-absorbing (versus the original energy-dissipating) designs.

Purpose: To evaluate the efficacy and effectiveness of both types of hip protectors.

Methods: Relevant studies were identified among electronic databases (PubMed, CINAHL, EMBASE, Scopus, ProQuest Dissertations, Web of Science), reference lists, grey literature and specific journals. Those that met inclusion criteria were evaluated using a methodological quality scale designed to rate both randomized and non-randomized trials.

Results: Recent systematic reviews focusing on intention to treat (ITT) analyses conclude that hip protectors have limited efficacy. However, because poor compliance is a known problem with hip protectors, ITT results will mix the effects of non-compliance with any true efficacy effects. Per protocol analyses, while potentially biased, are more suggestive of efficacy: of 311 hip fractures, in intervention groups from 14 trials, only 19% were observed in patients who were wearing protectors.

Conclusion: The true efficacy of hip protectors may have been underestimated in previous reviews, and their effectiveness may be low due primarily to poor compliance.


D. R. Brenner (1,2); J. R. McLaughlin (1,2,3); R. J. Hung (1,2)

Author References

  1. Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario
  2. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  3. Cancer Care Ontario, Toronto, Ontario

Previous respiratory diseases and risk of lung cancer: a systematic review and meta-analysis

Purpose: To review the epidemiologic evidence of previous lung diseases as risk factors for lung cancer.

Methods: Relevant studies were identified through MEDLINE searches and reference reviews. Risk estimates across studies were calculated using random effects models.

Results: A previous history of COPD, chronic bronchitis or emphysema conferred a combined increased relative risk (RR) across 24 studies (RR = 1.68, 95% confidence interval [CI]: 1.49 to 1.90) and when examining studies with smokers, with people who had never smoked (“never smokers”), and across different diagnostic criteria. The combined effects from all 17 studies examining pneumonia suggest an increase in lung cancer risk (RR = 1.55, 95% CI: 1.34 to 1.79). A previous history of tuberculosis conferred an increase in lung cancer risk among all 23 studies (RR = 1.70, 95% CI: 1.42 to 2.02) and among only “never smokers.”

Conclusions: Previous lung diseases are associated with an increased risk of lung cancer among smokers as well as among “never smokers.” The evidence among “never smokers” supports a direct relationship between previous lung diseases and lung cancer.


E. Candido (1,2); L. D. Marrett (1,2)

Author References

  1. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  2. Population Studies and Surveillance, Cancer Care Ontario, Toronto, Ontario

Trends in thyroid cancer incidence in Ontario, Canada, from 1985 to 2004

Background: Over the past 30 years, the incidence of thyroid cancer has increased substantially in many developed countries, especially among women.

Purpose: To assess trends in the incidence of thyroid cancer in Ontario, Canada.

Study Design: Population-based cohort.

Methods: Thyroid cancer cases among patients aged 15 years plus were extracted from the Ontario Cancer Registry, 1985–2004 (n = 15 763). Age-standardized incidence rates were calculated. Trends were analysed using joinpoint regression; rate ratios were used to assess geographic variation.

Results: From 1985 to 2004, thyroid cancer incidence rates more than tripled in Ontario, from 5.1 to 16.3 per 100 000. Among men, incidence increased by 5.4% (95% confidence interval [CI]: 4.6 to 6.1) annually. The rate of increase among women was comparable to that of men until 1998, but accelerated thereafter (average annual increase 12.3%, 95% CI: 9.5 to 15.1). Significant variations in incidence rates and average annual increases were observed across geographic regions.

Conclusion: Increases in thyroid cancer incidence likely reflects changes in diagnostic practices leading to incidental detection of subclinical tumours. The accelerated rise in incidence among women and the geographic variation may reflect differences in health care access and utilization behaviours. Increased exposure to an unknown risk factor and/or immigration from high-incidence regions may also partly explain the rise in thyroid cancer.


H. Coo (1); H. Brown (1); H. Ouellette-Kuntz (1,2); M. Lam (1); C. T. Yu (3,4); M. Breitenbach (5); P. Hennessey (6); J. Holden (7); A. Noonan (8); R. Gauthier (9); L. Crews (9)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Ongwanada, Kingston, Ontario
  3. St. Amant Research Centre, Winnipeg, Manitoba
  4. University of Manitoba, Winnipeg, Manitoba
  5. Department of Education and Early Childhood Development, Charlottetown, Prince Edward Island
  6. Department of Health and Community Services, St. John’s, Newfoundland and Labrador
  7. Department of Psychiatry and Department of Physiology, Queen’s University, Kingston, Ontario
  8. Public Service Commission, Charlottetown, Prince Edward Island
  9. Department of Education, St. John’s, Newfoundland and Labrador

Age at first diagnosis of an autism spectrum disorder in different regions of Canada

Background: Early diagnosis of autism spectrum disorders (ASDs) reduces family stress and may lead to better outcomes. There are no empirical Canadian data on age at first diagnosis.

Purpose: To examine: 1) age at diagnosis in different regions of Canada; 2) whether diagnosis is occurring at earlier ages; and 3) the association between certain factors and age at diagnosis.

Study Design: Descriptive/cross-sectional.

Methods: Data were collected as part of a Canadian ASD surveillance program (National Epidemiologic Database for the Study of Autism in Canada). The sample included children living in one of six surveillance regions who were first diagnosed between 1997 and 2005. We used the Kruskal-Wallis test, Spearman’s rank correlation and linear regression models to examine our objectives.

Results: There were significant geographic differences in age at diagnosis (p < 0.001). No decreases in age at diagnosis were found, and there was a significant increase in southeastern Ontario (p = 0.004). Asperger disorder, Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS), birthplace outside of Canada and Aboriginal identity were associated with later age at diagnosis in one or more regions.

Conclusions: Canadian children with an ASD are not being diagnosed at as young an age as the literature suggests they could be. Future studies could examine waiting times for assessment, which may affect age at diagnosis.


M. Coghlan (1); S. Macdonald (1,2)

Author References

  1. Centre for Addictions Research of British Columbia, Victoria, British Columbia
  2. School of Health Information Science, University of Victoria, British Columbia

The role of substance use or gambling and psychosocial characteristics in explaining unintentional injuries

Background: Few studies exist that examine the associations between substance use or gambling, and unintended injuries.

Purpose: To investigate the relationship between the use of various substances or gambling and selected psychosocial characteristics with unintentional injury.

Study Design: Cross-sectional data were collected from groups of subjects in treatment for a primary problem with cocaine (n = 300), cannabis (n = 128), alcohol (n = 110), other drugs (n = 35), tobacco (n = 249) or gambling (n = 100).

Methods: The participants completed a self-administered questionnaire that included questions on various psychosocial scales (i.e. risk taking/impulsivity, chronic stress, coping, and social supports), frequency of drug and alcohol use or gambling and unintentional injuries in the year prior to treatment.

Results: For the univariate analyses, both frequency of cocaine and cannabis use, risk taking/impulsivity, stress and coping were significantly related to injuries. For the multivariate analyses, only risk taking/impulsivity, stress, age and sex were significantly related to injuries.

Conclusion: The results provide important information regarding factors associated with reported injuries among individuals in addictions treatment.


M. L. Costa (1); L. D. Marrett (1,2)

Author References

  1. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  2. Population Studies and Surveillance, Cancer Care Ontario, Toronto, Ontario

Melanoma incidence trends among young adults in Ontario: boom or bust?

Background:Recent evidence suggests a rise in melanoma incidence among young adults in the US, particularly women, coinciding with changing ultraviolet ray (UVR) exposures in this age group.

Objective:To describe recent trends in melanoma incidence for young adults in Ontario.

Study Design:Population-based, retrospective cohort study.

Methods:Ontario Cancer Registry (1970–2004) data were used to calculate incidence rates for young adults aged 15 to 34 years by sex (n = 5 294). Birth cohort effects were examined, and time trends were assessed in joinpoint analyses.

Results: Melanoma incidence nearly doubled for young adults between 1970 and 2004, from 3.2 to 5.6 per 100 000. Incidence increased at a rate of 3.5% for women (95% confidence interval [CI]: 2.4 to 4.6) and 2.5% for men (95% CI: 1.2 to 3.8) from 1970 to 1987, and stabilized thereafter. Age-specific incidence increased steadily with each successive cohort born before 1950, with this increase more predominate for men.

Conclusions:Our findings confirm previous evidence of a rise in melanoma incidence among young adults; however, further research is needed to determine its etiology.


J. Cushon (1); N. Muhajarine (1,2)

Author References

  1. Department of Community Health and Epidemiology, University of Saskatchewan, Saskatoon, Saskatchewan
  2. Saskatchewan Population Health and Evaluation Research Unit, Saskatoon, Saskatchewan

Globalization and child health: evidence from Saskatoon, Saskatchewan

Background: Globalization influences the determinants of child health. However, there are only a limited number of empirical studies that have sought to link the macro-level processes of globalization to health effects at the local level.

Purpose: To investigate the political and economic pathways by which globalization affects the determinants of health and health outcomes in Saskatoon, Saskatchewan, with special reference to low-income children.

Study Design and Methods: A case study design which emphasized mixed methods—a demographic profile, an environmental scan of child-relevant public policy, process tracing, interviews (n = 26)—and triangulation with joinpoint regression and logistic regression with generalized estimating equations. The analytical framework for this study was developed by Labonte and Torgerson (2005).

Results: Globalization has likely contributed to a retrenchment of the welfare state (e.g., decreased social spending, the privatization of risk), deepened poverty among those that were already vulnerable to poverty (e.g., low-income gap increased by $2500 in Saskatoon since 1980, increased food bank usage), increased income inequality, labour market restructuring (e.g., non-traditional employment arrangements were more common), and decreased housing affordability in Saskatoon (e.g., the average Multiple Listing Service price on a home was $76,008 in 1990, and this increased to $232,754 in 2007). Further research is required to determine if these changes have contributed to increasing disparities in child health outcomes.

Conclusions: These findings suggest the need for policy and program responses that address the changes to the determinants of child health posed by globalization.


J. M. DeGroot (1,2); M. Brundage (2); M. Lam (1); S. L. Rohland (2); J. Heaton (3); W. J. Mackillop (1,2); D. R. Siemens (3); P. A. Groome (1,2)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Division of Cancer Care and Epidemiology, Queen’s Cancer Research Institute, Queen’s University, Kingston, Ontario
  3. Department of Urology, Queen’s University, Kingston, Ontario

Survival differences among prostate cancer patients treated by radical prostatectomy versus curative radiotherapy

Background: The relative effectiveness of treatment with radiotherapy versus surgery for prostate cancer is uncertain, and randomized clinical trials are unlikely to be performed to provide conclusive evidence.

Purpose: To examine the cause-specific survival difference between radiotherapy and surgery for localized prostate cancer, recognizing that observational data may contain residual confounding.

Study Design: This was a population-based, case-cohort study of curative prostate cancer patients in Ontario diagnosed between 1990 and 1998. Cases were oversampled and died of prostate cancer within ten years.

Methods: Patients were identified using the Ontario Cancer Registry and their charts were reviewed on-site by trained abstractors. Survival differences between radiotherapy and surgery candidates were analyzed using Cox-proportional hazard regression controlling for known covariates. Traditional multivariate and propensity score analyses were used.

Results: The hazard ratio for prostate cancer death for radiotherapy compared to surgery candidates was 1.44 (95% confidence interval [CI]: 0.86 to 2.40) for the overall population, 1.58 (95% CI: 0.37 to 6.67) for low risk patients and 1.34 (95% CI: 0.77 to 2.32) for intermediate risk patients. Hazard ratios from the lowest to highest propensity score quintiles were 0.30 (95% CI: 0.04 to 2.28), 1.54 (95% CI: 0.35 to 6.77), 0.90 (95% CI: 0.29 to 2.82), 2.71 (95% CI: 1.01 to 7.31) and 1.08 (95% CI: 0.41 to 2.81).

Conclusion: There may have been a slight advantage of surgery over radiotherapy between 1990 and 1998, the period being studied.


P. A. Demarsh, J. Little, B. Wilson

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario

Genetic variation as a potential mediator of NSAID prophylaxis for colorectal neoplasia

Background: Colorectal cancer (CRC) is a common and often deadly disease. Non-steroidal, anti-inflammatory drugs (NSAIDs) are known preventive agents, but the risk of complications limits their use in average-risk populations. There is some evidence that individual responses are influenced by inherited genetic variation. A profile incorporating variant genes that alter individual responses to NSAIDs could be used to predict responders.

Purpose: To develop and assess a genetic profile to predict NSAID effectiveness for the prevention of CRC. Study Designs: Systematic review and case-control study.

Methods: 1. MEDLINE, EMBASE and HuGE Published Literature Database were used to identify relevant research findings. Abstracts were screened by parallel reviewers, and data were extracted from articles that met inclusion criteria. 2. The Assessment of Risk for Colorectal Tumors in Canada dataset was used to investigate interactions between genotype and NSAID use. DNA was obtained from 1 231 cases (selected at random from the population-based Ontario Familial Colorectal Cancer Registry) and 1 240 age-matched controls from the general population. Single nucleotide polymorphisms were analyzed using the Affymetrix GeneChip Human Mapping 100K Set. NSAID use was determined through questionnaires completed at enrolment. Odds ratios and interactions were assessed using logistic regression, adjusted for potential confounders.

Results: Pending.

Conclusions: Pending.


B. Denning (1,2); D. Hunter (1); S. Chatwood (2)

Author References

  1. Queen’s University, Kingston, Ontario
  2. Arctic Health Research Network, Yellowknife, Northwest Territories

Place of residence and childbirth outcome in the Northwest Territories

Background: In the Northwest Territories (NWT), women residing in Yellowknife, Inuvik and Fort Smith have access to continuity of caregiver and various prenatal classes and social programs. Women residing outside of these communities are transferred to a larger centre at 37 weeks gestation and do not have access to these resources during their pregnancy.

Purpose: To examine the relationship between place of residence and neonatal outcome within the NWT.

Study Design: A cohort study, in which women will be grouped in either a “non-transfer” group or in a “transfer” group, depending on their place of residence. A negative neonatal outcome will be recorded if the newborn is stillborn or exhibits one or more of the following: a five-minute Apgar score of less than seven, a birth weight of less than 2 500 grams or a birth weight of more than 4 500 grams.

Methods: The data, obtained from the NWT Maternal Perinatal Committee, will be analyzed descriptively, compared using odds ratios while stratifying for potential confounders, and then analyzed using logistic regression to control for covariates.

Results: Pending.

Conclusions: This study aims to provide a more accurate picture of the effects of availability of care on neonatal health outcome.


J. Dennis, J. Little

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario

Systematic review of the utility of the case-only design to detect gene-environment and gene-gene interactions

Background: The case-only study, proposed as a design specifically for assessing departure from multiplicative gene-environment and gene-gene effects, is of considerable potential value, but there are concerns about its validity.

Purpose: To evaluate the extent and sources of bias arising from the application of the case-only design in studies of gene-gene and gene-environment interaction.

Study Design: Systematic review and meta-regression analysis.

Methods: Study inclusion criteria were a theoretical or empirical evaluation of the case-only study design for the investigation of genetic interaction in disease. Qualitative comments on the potential for bias in the case-only study were extracted.

Results: A search of MEDLINE, CINAHL, EMBASE, and PUBMED yielded 294 unique articles. The full text of 190 articles was screened and 26 met the final inclusion criteria. Of the 17 empirical evaluations identified, 13 were comparisons of the case-only and case-control designs. Information required for the meta-analysis was missing in nine of these 13 studies.

Conclusions:The case-only design is susceptible to bias caused by non-independence of genetic and environmental factors in the source population, which can be difficult to assess. The methodological features of a study may influence the amount of bias in case-only interaction estimates. Next steps include a meta-regression analysis to quantify the extent and sources of bias in case-only studies.


M. T. Do (1,2); L. D. Marrett (1,2); J. Purdham (2,3); W. Lou (2); J. I. Payne (2,4)

Author References

  1. Population Studies and Surveillance, Cancer Care Ontario, Toronto, Ontario
  2. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  3. Gage Occupational and Environmental Health Unit, University of Toronto, Toronto, Ontario
  4. Department of Diagnostic Radiology, Dalhousie University, Halifax, Nova Scotia

Ionizing radiation exposure and risk of gastrointestinal cancer: a study of Ontario uranium miners

Purpose: To determine the relationship between exposure to radon decay products and the incidence of and mortality from gastrointestinal (esophagus, stomach, and colorectal) cancer for a cohort of 28 273 eligible Ontario uranium miners. Radon exposures measured in Working Level Months (WLM) were previously estimated for each miner.

Methods: Cancer diagnoses between 1964 and 2004 and cancer deaths between 1954 and 2004 in Ontario were determined by record linkage with the Ontario Cancer Registry. Non-cancer deaths were also ascertained from the Ontario mortality file, 1954–2004, to calculate person years at risk. Poisson regression methods for grouped data were used to estimate the relative risks (RR).

Results: Compared to miners with 0 WLM, those with the highest cumulative exposure (>40 WLM) had significantly higher relative risk of both stomach cancer (RRIncidence = 2.30, 95% confidence interval [CI]: 1.02 to 5.17 and RRMortality = 2.90, 95% CI: 1.11 to 7.63) and colorectal cancer (RRIncidence =1.56; 95% CI: 1.07 to 2.27 and RRMortality = 1.74; 95% CI: 1.01 to 2.99) after adjusting for age at risk and period effects. However, no relationships were observed for esophageal cancer. Effect modifications were also observed for duration of employment and years since last employment.

Conclusions: These results suggest that exposure to radon decay products among Ontario uranium miners significantly increases the risk of diagnosis and death from stomach and colorectal cancers.


A. Dudani (1); A. Macpherson (2); H. Tamim (2)

Author References

  1. Department of Psychology, York University, Toronto, Ontario
  2. School of Kinesiology and Health Science, York University, Toronto, Ontario
  3. Gage Occupational and Environmental Health Unit, University of Toronto, Toronto, Ontario

Are Canadian children with behaviour problems at higher risk of injury?

Background: While an association between behaviour problems and childhood injuries has been posited, most studies have been cross-sectional and have not considered comorbidity.

Purpose: To prospectively assess the relationship between behaviour problems and the risk of unintentional injuries in a population-based sample of Canadian children.

Study Design: Prospective cohort.

Methods: Data from the Canadian National Longitudinal Survey of Children and Youth were used. The outcome was injury in Cycle 1 (1994-95). The exposure was the presence of behaviour problems in Cycle 2 (1996-97), defined as children with hyperactivity only, aggression only, anxiety only, hyperactivity with aggression, hyperactivity with anxiety, aggression with anxiety, and hyperactivity with aggression and anxiety. Covariates included child-related, parental and social-environmental factors.

Results: The final weighted longitudinal sample included 2 209 886 children, of which 251 927 (11.4%) were injured two years later. Compared to children without behaviour problems, no behaviour group had significant risk of injury two years later. However, children who lived with a single parent or no parent and children who did not live with a biological parent had significantly greater risk of injury.

Conclusions: We need to look beyond behaviour problems, and possibly at parental and family factors, in order to reduce the burden of injuries for Canadian children.


B. T. Dufault, N. Klar, Y. H. Choi

Author References

  1. University of Western Ontario, London, Ontario

The quality of cross-sectional ecological studies published since 2000: a bibliometric review

Background: The ecological study design is routinely used by epidemiologists in spite of its limitations. How well the challenges of the design are dealt with in epidemiological research is presently unknown.

Purpose: To evaluate the design, statistical methodology and reporting of modern cross-sectional ecological papers.

Study Design: Bibliometric review.

Methods: A search through the following journals identified all cross-sectional ecological studies published since January 1, 2000: American Journal of Epidemiology, Annals of Epidemiology, Epidemiology, International Journal of Epidemiology, Journal of Clinical Epidemiology and the Journal of Epidemiology and Community Health. All articles were assessed according to common evaluative criteria.

Results: Of the 117 cross-sectional ecological papers that met the inclusion requirements, many use unreliable methodologies or commit statistical oversights; most of the papers that adjusted their outcomes for age or sex did so incorrectly (59%, 69/117), only one paper performed sample size calculations, and simple linear regression was the most common analytic approach (39%, 46/117). Also, many papers omitted important information when discussing the ecological nature of their study (31%, 36/117), intended levels of inference (40%, 47/117) and the susceptibility of their research to the ecological fallacy (51%, 60/117).

Conclusion: There is a need for an international set of guidelines that standardizes the reporting of ecological studies.


A. Durbin (1); R. Callaghan (1,2); F. Matheson (1,3)

Author References

  1. Community Health and Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  2. Centre for Addiction and Mental Health, Toronto, Ontario
  3. Keenan Research Centre, St Micheal’s Hospital, Toronto, Ontario

Hospitalization for psychosis among immigrants: a systematic review

Background: Hospitalization is among the most expensive and intrusive strategies for managing mental illness. Immigrant groups are at high risk for developing serious mental illness including psychosis, one of the most disabling mental disorders. Better understanding of immigration as a risk factor for hospitalization is important to target other interventions and reduce risk.

Purpose: To investigate if immigrant groups to developed European countries are at increased risk of hospitalization for psychosis.

Study Design: A systematic qualitative literature review.

Methods: MEDLINE, EMBASE, CINAHL and PsycINFO databases were systematically searched for potentially relevant publications between January 1977 and February 2009 using search terms pertaining to schizophrenia or psychosis, hospitalization and immigrants.

Results: Based on the application of nine inclusion criteria, five studies were assessed. These were summarized systematically for each of the inclusion criteria. Most studies reported that foreign-born persons had higher hospital first-admission rates for schizophrenia and psychosis than did native-born persons, although this difference did not reach significance for all immigrant groups.

Conclusion: The elevated rates of hospitalization for psychosis for immigrants raise questions about the availability of alternative management strategies.


A. Durbin

Author References

  1. Community Health and Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario

Manifestations of stigma against persons with mental illness: a literature scan

Background: Despite the pervasiveness and burden of mental disorders, approximately two-thirds of people with mental disorders do not seek treatment. One of the chief reasons often cited for this is stigma, which may be defined as “invalidating and poorly justified knowledge structures that lead to discrimination.” The Mental Health Commission of Canada (2006) identified nine areas where stigma reduction is a priority.

Purpose: To investigate the effect of stigma on persons with mental illness in Canadian society by reviewing the literature.

Study Design: Nine issues identified by the Commission were used to guide an environmental scan of stigma research.

Methods: PsycINFO, MEDLINE, WebSPIRS and CSA Sociological Abstract were searched using the terms mental illness, mental health, health care and stigma. Relevant Canadian and American legislation documents were also consulted.

Results: The robust influence of stigma against persons with mental illness was identified in segments of Canadian society including the workplace, education system, criminal justice system, accessible housing, media coverage, treatment delivery, insurance coverage, mental health funding and rights.

Conclusion: Stigma against persons with mental illness has a strong influence in an array of sections of Canadian society and may be reduced by anti-stigma campaigns.


M. Eshoul (1); D. Stieb (1,2); K. Brand (3)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Air Quality Health Effects Research Section, Health Canada, Ottawa, Ontario
  3. School of Management and Institute of Population Health, University of Ottawa, Ottawa, Ontario

Analysis of the impact of air pollution on life expectancy and quality of life in Canada

Background: Many studies have linked air pollution with increased mortality risk and increased incidence of certain chronic conditions, such as chronic bronchitis (CB) and acute myocardial infarction (AMI). Air pollution is estimated to cause approximately two million premature deaths annually worldwide. Therefore, it is essential to determine the effects of air pollution on human health to help with decisions regarding air pollution policies.

Purpose: To determine the impact of two air pollutants, ozone and fine particulate matter (PM2.5), on life expectancy and quality of life of Canadians.

Study Design: This proposal relies upon pre-existing PM2.5 long-term exposure studies with cohort designs to estimate the response function between exposure levels and health outcomes. The estimates of the response function for ozone come from multi-site time-series and meta-regression studies.

Methods: The analysis will employ life table methods, together with utility-based health status measures and concentration-response functions. The impacts of uncertainty will be assessed using sensitivity analysis and Monte Carlo simulation.

Results: Pending. Estimates of lost years of life due to ozone and lost quality-adjusted life year (QALYs) associated with chronic morbidity related to PM2.5 will be generated.

Conclusions: Pending. Sensitivity of findings to alternative assumptions and primary sources of uncertainty will be evaluated.


J. Essue (1,2); P. Marks (2); M. Gignac (3); C. Borkhoff (4); X. Cao (3); L. White (5); M. Hurtig (6); I. Weller (2)

Author References

  1. Schulich School of Medicine and Dentistry, Department of Medicine, University of Western Ontario, London, Ontario
  2. Sunnybrook Health Sciences Centre, Toronto, Ontario
  3. Toronto Western Hospital, Toronto, Ontario
  4. Women’s College Hospital, Toronto, Ontario
  5. Mount Sinai Hospital, Toronto, Ontario
  6. University of Guelph, Comparative Orthopaedic Research Laboratory, Guelph, Ontario

Measurement testing of an exercise intentions questionnaire in patients after anterior cruciate ligament reconstruction

Background: The measurement properties of an exercise intentions measure (EIM) have not been evaluated in patients following anterior cruciate ligament (ACL) reconstruction.

Purpose: To evaluate measurement properties of an EIM five to 11 years after ACL reconstruction.

Methods: Sixty patients (27 women) who underwent ACL reconstruction 6.4 ± 2.0 years ago were recruited. Patients completed the EIM (3 domains: identity, commitment and beliefs) and the Minnesota leisure time physical activity questionnaire (MLTPAQ). Test-retest reliability of the EIM was assessed on a sub-sample of 48 patients (23 women) by intra-class correlation coefficient (ICC). Construct validity was assessed by correlating the EIM with MLTPAQ. Item response distributions, inter-item correlations and Cronbach’s alpha were assessed.

Results: There was a good distribution of responses across all items. Cronbach’s alpha for the identity (0.96), commitment (0.89) and beliefs (0.79) domains indicated good internal consistency for each sub-scale. Test-retest reliability (ICC) was excellent for the identity (0.82) and commitment (0.83) domains and good for the beliefs domain (0.77). Time spent in conditioning activities (hrs/week) correlated significantly only with the identity (0.37, p > 0.01) and commitment (0.35, p > 0.01) domains providing evidence for construct validity.

Conclusion: The identity, commitment and beliefs domains demonstrate good reliability and internal consistency in a sample of 60 patients five to 11 years after ACL reconstruction.


J. Evans (1); D. Krewski (2)

Author References

  1. Department of Community Medicine and Epidemiology, University of Ottawa, Ottawa, Ontario
  2. R. Samuel McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario

An estimation of the global burden of disease (GBD) due to particulate air pollution

Background: Determining air pollution concentrations through satellite imagery is useful when ground level monitoring is not employed. It may be an important tool when assessing global impacts of air pollution.

Purpose: To assess global mortality that can be attributed to chronic exposure to fine particulate air pollution (PM2.5) using remote sensory data.

Study Design: Cross-sectional mortality incidences were related to PM2.5 concentrations by mortality-PM2.5 risk coefficients to provide attributable mortality estimates. Risk coefficients were previously derived from the American Cancer Society Cancer Prevention Study II prospective cohort.

Methods: Average PM2.5 concentrations from 2001–2006 were obtained for 181 countries based on satellite imagery methods. PM2.5 concentrations were weighted to a 2005 population. All-cause, lung cancer, respiratory disease, ischemic heart disease, cardiovascular disease and cardiopulmonary mortality incidences were extracted from the WHO Mortality Database at the country level for 2005. The burden of mortality attributable to PM2.5 is estimated by incorporating PM2.5 concentrations, mortality incidences and risk coefficients in various statistical models. The sensitivity of mortality estimates to changes in model selection and input parameters will be explored, and uncertainty in the model parameters will be propagated into uncertainty in risk estimates.

Results: Pending. Research in progress.

Conclusions: Pending.


T. Fang (1); L. M. Campbell (1,2); Y. X. Wang (2); K. Aronson (3)

Author References

  1. School of Environmental Studies, Queen’s University, Kingston, Ontario
  2. Department of Biology, Queen’s University, Kingston, Ontario
  3. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario

Assessing human exposure to mercury from fish in east China lakes

Background: Mercury is a commonly known neurotoxin that causes a series of adverse effects on humans under acute, high exposure or long-term exposure. Vulnerable populations include pregnant women, children and frequent fish consumers. Because of rapid industrial development and the importance of freshwater fish in the Chinese diet, contamination by mercury and other metals are of increasing concern. Preliminary studies indicate elevated total mercury concentrations in four economic species from Qiandao Lake, a 50-year-old reservoir in east China. Two catfish species also exceed the Chinese mercury contamination limit (0.3 ng/g). Since fish is of great importance in local dietary patterns and to the regional tourism industry, the extent to which fish consumption could be a potential health risk was evaluated.

Purpose: To determine the relationship of fish consumption patterns and mercury levels in female residents of reproductive age (17-44 years) from the Qiandao Lake region.

Methods: A cross-sectional epidemiological study using hair samples and dietary interviews was carried out in a lakeside fishing town. Hair samples were collected from local female residents for laboratory analysis of mercury and other metals.

Results: Pending. Research in progress.

Conclusion: Pending.


N. Farhat (1); D. Krewski (1); T. Ramsay (1); R. Burnett (2)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Biostatistics and Epidemiology Division, Health Canada, Ottawa, Ontario

The association of ozone and fine particulate matter with mortality and hospital admissions in 12 Canadian cities

Background: Recent epidemiological studies have linked health effects to air pollution exposure at levels commonly found in North America.

Purpose: To determine the impact of short-term exposure to ozone and PM2.5 on mortality and hospital admissions in different age groups and to examine the sensitivity of the results to seasonality control and exposure lag period.

Design: Time-series study.

Methods: City-specific risks were estimated with Poisson regression models using data collected over a 20-year period. Risks were pooled across cities using the inverse variance weighting method.

Results: Results suggest statistically significant associations across all outcomes except cardiovascular hospital admissions. Significant central estimates of the increase in mortality and respiratory hospital admissions are associated with a 10 ppb increase in the one-hour maximum ozone levels or a 10 μg/m3 increase. The 24-hour mean PM2.5 levels ranged from 0.56% (95% confidence interval [CI]: 0.27% to 0.84%) to 3.17% (95% CI: 0.61% to 5.72%). Generally, stronger associations were found among seniors. Effect estimates were robust to adjustment for seasonality confounding but were sensitive to lag period.

Conclusion: Considering the size of the population exposed to air pollution, reductions in ozone and particulate matter would likely lead to considerable health benefits and reduce premature deaths and hospital admissions.


A. Faye (1); B. E. Alvarado (2); M. V. Zunzunegui (1)

Author References

  1. Département de médecine sociale et préventive, Université de Montréal, Montréal, Quebec
  2. Department of Epidemiology and Biostatistics, McGill University, Hamilton, Ontario

Screening for prostate cancer in community-dwelling men in São Paulo: what are the contributing factors?

Background: Prostate cancer is one of the leading causes of death among older men. The American Cancer Society recommends a yearly examination of the prostate to screen for this disease in all men over 50 years of age.

Purpose: To examine the factors related to screening for prostate cancer among men aged 60 plus living in São Paulo, according to the Andersen sociobehavioural model.

Methods: Data were taken from the Study of Ageing and Health in Barbadian Elders survey conducted in Latin America and the Caribbean in 2000. Logistic regressions were used to analyze the association of predisposing factors, enabling resources and health needs with prostate examination among 881 men aged 60 and over living in the city of São Paulo.

Results: Prevalence of prostate examination was 0.39. In multivariate analyses, participants who were more likely to have had a prostate exam in the previous two years were those with a higher education (odds ratio [OR] = 3.13, 95% confidence interval [CI]: 1.51 to 6.51), were married (OR = 1.70, 95% CI: 1.13 to 2.55), had higher comorbidity (OR = 1.23, 95% CI: 1.05 to 1.45) and had private health insurance (OR = 1.92, 95% CI: 1.16 to 3.43) or public health insurance (OR = 1.70, 95% CI: 1.13 to 2.55) compared with social security.

Conclusion: Prostate cancer screening training seems necessary for primary care physicians working in the social security system.


A. J. Ferro (1); D. J. DeWit (1,3); S. Wells (1,3); K. N. Speechley (1,2,4,5)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Paediatrics, University of Western Ontario, London, Ontario
  3. The Social, Prevention and Health Policy Research Department, Centre for Addiction and Mental Health, Toronto, Ontario
  4. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario
  5. Children’s Health Research Institute, London, Ontario

The association between environmental factors and the quality of Big Brothers Big Sisters of Canada community match relationships: a thesis proposal

Background: Empirical evidence suggests that environmental factors (parental support, caseworker support, mentor training) and mentor self-efficacy are positively associated with match relationship quality (MRQ) between children and adult mentors enrolled in Big Brothers Big Sisters (BBBS) programs. Further evidence points to positive associations between environment and self-efficacy. However, the extent to which mentor self-efficacy mediates (or accounts for) the relationship between environmental supports and MRQ remains unclear.

Hypotheses: (1) Environmental supports (caseworker support, parental support and mentor training) will each be positively associated with MRQ; (2) The positive relationships between environmental supports and MRQ will be mediated by mentor self-efficacy. The plausibility of the mediation model will be explored across categories of children’s age and gender and match gender composition.

Study Design: A cross-sectional study involving 300 families and mentors will be conducted using the 12-month follow up data from an on-going longitudinal investigation of BBBS community match relationships across Canada.

Methods: Data are collected via in-person interviews for children and self-administered questionnaires for mentors and parents. Structural equation modelling will be used to address the study objectives including mediation and moderation analyses.

Results: Pending.


M. A. Ferro (1,5,6); K. N. Speechley (1,2,5,6); W. R. Avison (1,2,3,5,6); M. K. Campbell (1,2,4,5,6)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Paediatrics, University of Western Ontario, London, Ontario
  3. Department of Sociology, University of Western Ontario, London, Ontario
  4. Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario
  5. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario
  6. Children’s Health Research Institute, London, Ontario

A prospective study of depressive symptoms in mothers of children with new-onset epilepsy: preliminary results

Purpose: 1) To estimate the prevalence and course of depressive symptoms in mothers of children with new-onset epilepsy; and 2) to determine maternal, child and family risk factors for depressive symptoms at 12 months after onset and changes in levels of depressive symptoms over the 12 months after onset.

Methods: Data were obtained from a national prospective study of children 4 to 12 years old with new-onset epilepsy followed for 24 months. Maternal depressive symptoms (MDS) were measured using the Center for Epidemiologic Studies Depression Scale (CES-D) and analyzed using a multilevel model for change over 12 months.

Results: Of the 349 mothers of children with new-onset epilepsy who participated, over one-third (36%) were at risk for clinical depression (CES-D >= 16); however, the proportions of mothers at risk decreased over time. Predictors of depressive symptoms at 12 months were younger maternal age, CES-D >= 16 at baseline, worse child health-related quality of life, less family resources, more family demands and worse family functioning. Predictors of change in depressive symptoms were CES-D >= 16 at baseline and more family demands.

Conclusions: Maternal, child and family factors play a role in predicting MDS among mothers of children with new-onset epilepsy at 12 months and in predicting a change in MDS within the first 12 months, and may be targets for intervention.


J. Fralick, W. Parulekar, P. A. Groome, W. J. Mackillop

Author References

  1. Division of Cancer Care and Epidemiology, Cancer Research Institute, Queen’s University, Kingston, Ontario

A population-based description of the incidence and survival for inflammatory breast cancer in Ontario. 1984–2005

Background: Inflammatory breast cancer (IBC) is a rare, aggressive form of breast cancer with poor survival rates.

Purpose: To describe the incidence and survival for pathologically confirmed IBC.

Study Design: Retrospective, population-based, cohort study.

Methods: Women with IBC were identified in the Ontario Cancer Registry by the histology code 85303 and their data linked to Canadian census data. Age-adjusted incidence rates of IBC were calculated using the direct method. Kaplan-Meier survival curves were calculated to describe the overall survival (OS). Comparisons were also made over two time cohorts, 1984–1994 and 1995–2005.

Results: Between 1984 and 2005, 1 034 cases of pathologically confirmed IBC (0.8% of all breast cancers) were identified in Ontario. Age-adjusted incidence rates of IBC doubled from 0.57 cases per 100 000 women-years in 1984–1987 to 1.15 cases in 2003–2005. Five- and 10-year OS was 34.6% and 21.5%. Ten-year OS increased from 12.0% (95% confidence interval [CI]: 8.3 to 16.3) for patients diagnosed in 1984–1994 to 24.0% (95% CI: 20.1 to 28.2) for patients diagnosed in 1995–2005.

Conclusions: The incidence of IBC appears to have increased over time. We observed a temporal trend towards an improved 10-year OS. Further study will determine if temporal variations in disease management explain the improvement in OS.


P. Frenette (1); K. MacPherson (1); G. Flowerdew (1); D. Norris (2); E. Power (2)

Author References

  1. Department of Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia
  2. Department of Family Studies and Gerontology, Mount Saint Vincent University, Halifax, Nova Scotia

Exploring a possible relationship between residential setting and health service access by individuals living with intellectual disabilities in central Nova Scotia

Background: Individuals living with intellectual disabilities are at increased risk for developing health problems and face significant barriers to accessing quality health care. Of particular interest is the role that residential setting might play in health service accessibility within this population.

Purpose: 1) To describe health service access by individuals living with intellectual disabilities in central Nova Scotia; 2) to investigate the relationship between residential setting and access to health services within this population; and 3) to assess the relationship between residential setting and barriers to accessing health services.

Study Design: Cross-sectional.

Methods: Adults living with intellectual disabilities in central Nova Scotia will be identified through the Intellectual Disabilities Service Needs Research Alliance survey. Data on residential setting, perceived health care access and associated barriers will be extracted from the survey data and linked with measures of health care utilization and continuity of care from provincial physician billing and hospital discharge databases. Data will be analyzed using generalized linear models.

Results: Pending. Residential setting is expected to predict health service utilization, continuity of care, perceived health care accessibility and barriers to accessing care within this population.

Conclusions: The study will identify any existing disparities in health care accessibility among those living with intellectual disabilities in central Nova Scotia.


B. Gariepy (1,2); D. Nitka (1); N. Schmitz (1,2)

Author References

  1. Douglas Mental Health University Institute, McGill University, Lasalle, Quebec
  2. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec

Association of obesity and anxiety disorders in the population: a systematic review and meta-analysis

Background: There has been a growing interest in the associations of mental disorders and obesity. Previous obesity studies and reviews have largely focused on depression but no review has specifically addressed anxiety disorders.

Purpose: To systematically review the evidence for an association between obesity and anxiety disorders.

Methods: A systematic search to identify epidemiological articles reporting on obesity and anxiety was performed in seven major bibliographical databases. Two independent reviewers abstracted the data and assessed study quality. Pooled odds ratios (ORs) were calculated.

Results: Eighteen studies were included for review (two prospective and 16 cross-sectional). Measures of effect from prospective data were mixed, but cross-sectional evidence suggested a positive association between obesity and anxiety, notably in women. Eight studies were sufficiently homogeneous for meta-analysis: the overall pooled OR was 1.42 (95% confidence interval [CI]: 1.24 to 1.63). Subgroup analyses found a positive significant association in women (OR = 1.5, 95% CI: 1.1 to 2.1) but a non-significant association in men (OR = 1.3, 95% CI: 0.9 to 1.8).

Conclusion: A weak but positive association exists between obesity and anxiety disorders, especially among women. Limited longitudinal data restrict inference on the temporal relationship from obesity to anxiety. High quality prospective studies are therefore suggested.


C. Gaudet, Y. Chen

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario

Perceived mental health and unmet health care needs among Canadian women

Background: Women have a higher risk of unmet health care needs and of developing mood disorders.

Purpose: To examine the association between self-perceived mental health and unmet health care needs among Canadian women, 18 to 64 years old.

Study Design: A subset of the Canadian Community Health Survey Cycle 3.1 was analysed (n = 48 467).

Methods: The proportions of unmet health care needs according to known determinants, as well as the reasons given for the unmet health care needs were presented. Stratified analyses and multivariate logistic regressions were conducted.

Results: There was a strong association between fair/poor perceived mental health and perceived unmet health care needs (odds ratio [OR] = 2.70, 95% confidence interval [CI]: 2.19 to 2.79). Women who reported fair/poor mental health and demonstrated negativity were more likely to report unmet health care needs (OR = 4.45, 95% CI: 3.85 to 5.15) compared to women who did not demonstrate negativity. The number one reason for unmet health care needs was long wait times.

Conclusion: Canadian women who reported poorer mental health are facing barriers to health care. Reasons given for unmet health care needs do not vary according to perceived mental health.


A. Giacomazzo, H. Tamim

Author References

  1. School of Kinesiology and Health Science, York University, Toronto, Ontario

Prevalence and predictors of weight-control behaviours in Canadian youth

Background: Risky weight-control behaviours can have serious health consequences. Few studies of weight control behaviours have been completed within the Canadian youth population.

Purpose: To assess the prevalence and predictors of Canadian youth aged 12 to 17 who are currently trying to lose weight, as well as the prevalence and predictors of risky weight-control behaviours in youth 16 to 17 years old.

Study Design: Secondary analysis of the cross-sectional data from the National Longitudinal Survey for Children and Youth cycles 6 and 7. Data was collected from 2004–2007, although the nationally representative sample was drawn in 1994.

Methods: The main outcome variables are current weight-control behaviour and type of weight-control method. Variables will be considered against predictors (demographic, psychological and health-risk behaviours) at the bivariate level and, if found significant, regression analysis will be performed.

Results: Pending. This project is currently in the proposal stage and is in the process of being submitted to the Research Data Centre for access to the microdata.

Conclusion: The results will help to guide programs and policies that are aimed at promoting healthy weight management practices in youth.


M. González (1); R. J. Dennis (2,3); J. H. Devia (4); A. Jurado (5); D. Echeverri (6); G. Briceño (7); M. Mora (5); F. Gil (3)

Author References

  1. Public Health option in Epidemiology, Université de Montréal, Montréal, Quebec
  2. Fundacion Cardioinfantil, Institute of Cardiology, Bogotá, Colombia;
  3. Department of Clinical and Biostatistical Epidemiology, Javeriana University, Bogotá, Colombia
  4. Colombian National Federation of Coffee Growers of Colombia, Bogotá, Colombia
  5. Alberto Jurado Consulting, Bogotá, Colombia
  6. Cardiology and Hemodynamic, Foundation Cardio Infantile, Institute of Cardiology, Bogotá, Colombia
  7. Department of Research, Foundation Cardio Infantile, Institute of Cardiology, Bogotá, Colombia

Cardiovascular and chronic disease risk factors among Colombian coffee growers

Purpose: To estimate the prevalence and make comparative analyses of cardiovascular and chronic diseases risk factors in Colombian coffee growers, in 2007.

Methods: Cross-sectional study, multi-stage sampling by conglomerates. Questionnaires recommended by the Pan-American Health Organization were used to survey 2 516 men and women between 18 and 74 years old. Descriptive analyses with anthropometric and biochemical measurements on the magnitude of risk factors, based on socio-demographic variables, were made to evaluate possible differences in prevalence, bivariate analysis and logistic regression controlling by potential confounders. The results were compared with those of a decade-old national study of risk factors.

Results: Of the 2 516 people surveyed, 21.1% smoked (95% confidence interval [CI]: 20.97 to 21.23), 86.3% (95% CI: 86.19 to 86.41) ate less than the recommended five daily portions of fruits and vegetables, 30.2% (95% CI: 30.04 to 30.34) were physical inactive and 42.9% (95% CI: 42.74 to 43.06) were overweight or obese ; 26.2% had hypertension (95% CI: 26.06 to 26.34), 4.6% diabetes (95% CI: 4.53 to 4.67), and 62.1% abnormal blood lipids. The majority of participants (74,7%) had three simultaneous risk factors. Physical inactivity, obesity, abnormal blood lipids and diabetes were more prevalent among women (p < 0.01), and alcohol consumption and smoking among men (p < 0.01).

Conclusions: This study serves to orient health policies and interventions among Colombian coffee growers. Comparing these results with those from a 10-year-old national study of risk factors showed that there have been no significant changes.


H. Gordon (1); M. K. Campbell (1,2,3,4); K. N. Speechley (1,2,4); W. R. Avison (1,2,4,5)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Paediatrics, University of Western Ontario, London, Ontario
  3. Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario
  4. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario; Children’s Health Research Institute, London, Ontario
  5. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario

Adiposity and associated covariates in children born small for gestational age

Background: Children born small for gestational age (SGA), defined as a birth weight less than the 10th percentile, are at an increased risk for excess childhood adiposity.

Purpose: To differentiate risk levels among sub-groups of SGA children in order to determine whether excess childhood adiposity in this population is influenced by the etiologic factors which produced the SGA birth and/or postnatal factors such as nutrition, physical activity and child feeding practices.

Study Design: Follow-up of 134 SGA and 134 age- and sex-matched children who were average for gestational age (AGA) and whose mothers were part of a population-based cohort of 2 357 pregnant women from London, Ontario, recruited in 2001 as part of the Prenatal Health Project.

Methods: Participants will be interviewed in person at their residence where the height, weight and body fat percentage of their child will be measured. Parents will complete the Harvard Food Frequency Questionnaire, the Infant Feeding Questionnaire and the Child Feeding Questionnaire. They will also receive an accelerometer to be worn by the child for 4 days.

Results: Pending.

Conclusion: A prospective identification of risk factors for an adverse body composition will contribute to a more thorough understanding of the causal mechanisms at work and to secondary prevention strategies.


E. Graves (1); S. Evers (2); D. Hill (3,4,5); M. K. Campbell (1,3,5)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, Ontario
  3. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario
  4. Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario
  5. Department of Obstetrics and Gynaecology; Department of Paediatrics, University of Western Ontario, London, Ontario

Modifiable risk factors and excess fetal growth

Background: Recent studies have shown a strong relationship between glucose intolerance during pregnancy and adverse outcomes, including excess infant size, even for those below the threshold of gestational diabetes mellitus.

Purpose: To test the hypothesis that five factors (maternal pre-pregnancy body mass index [BMI], total kilocalorie intake, macronutrient distribution, omega-3 fatty acid intake and dietary vitamin D) are linked to maternal glucose intolerance during pregnancy, gestational diabetes mellitus and large-for-gestational-age (LGA) infant birth weight.

Study Design and Methods: This cohort study was superimposed on the framework of a longitudinal population-based cohort of 2 357 pregnant women. We excluded women with overt diabetes. Stepwise multinomial logistic regression was used, with a final statistical significance set at p = 0.05.

Results: Maternal BMI, height, antidepressant use, hyperemesis and pregnancy weight gain of over 18 kg were significantly associated with LGA birth. In a nested analysis, only maternal BMI and excessive pregnancy weight gain were found to influence the development of gestational diabetes mellitus. An additive interaction between excessive pregnancy weight gain and pre-pregnancy BMI on gestational diabetes mellitus was found.

Conclusions: Pre-pregnancy BMI and pregnancy weight gain of over 18 kg are modifiable risk factors that contribute to gestational diabetes mellitus and LGA delivery.


G. M. Hamilton (1); M. H. Meeuwisse (1); C. Emery (1); I. Shrier (2)

Author References

  1. Sport Injury Prevention Research Centre, University of Calgary, Calgary, Alberta
  2. Centre for Clinical Epidemiology and Community Studies, McGill University, Montréal, Quebec

An analysis of the definition of injury among Cirque du Soleil performers

Background: The preferred method of injury reporting is unknown and the definition of injury can produce shifts in the proportions of the reported injuries irrespective of the actual or real injury pattern.

Purpose: To explore how different methods of injury reporting affect the calculated 1) injury rates, 2) consequence, and 3) risk factor analysis.

Study Design: Cohort study.

Methods: Therapists used an electronic database as their sole charting procedure for Cirque du Soleil performers’ injuries and treatments between August 2004 and March 2008. We used two different injury definitions.

Results: There were 1 281 performers that met our inclusion criteria and these were followed for a total of 812 008 performances. The injury rate for medical attention injuries (9.5 injuries/1 000 adverse events [AEs], 95% confidence interval [CI]: 9.0 to 10.5) was higher than time loss injuries (1.5 injuries/1 000 AEs, 95% CI: 1.4 to 1.7). The consequence of injury (treatments and missed performances) for a time loss injury was greater than for medical attention injuries. Statistical significance of the incidence rate ratios differed between injury definitions.

Conclusions: The choice of injury definition can affect the interpretation of results from the same data; most notably the injury rate, the consequence of injury and the assessment of statistical significance for risk factors.


D. Harnett (1); P. Parfrey (2); J. Green (3); M. Woods (3); P. Rahman (4)

Author References

  1. Department of Clinical Epidemiology, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador
  2. Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador
  3. Discipline of Genetics, Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador
  4. Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador

The genetic basis of familial microsatellite stable colorectal cancer in Newfoundland

Background: Colorectal cancer (CRC) has a strong familial component but only a small proportion of incident CRC is attributable to mutations in known genes, the mismatch repair genes. In Newfoundland a substantial proportion of CRCs occur in cases with microsatellite stable (MSS) CRC who have a family history consistent with autosomal dominant disease.

Purpose: To genealogically connect two or more of the identified families to a common founder thus facilitating gene discovery.

Study Design: Seven families have been identified with CRC in multiple family members at the cancer genetics clinic, and DNA has been obtained. In addition, we have identified 44 cases in a population-based cohort who have MSS-CRC and a family history consistent with autosomal dominant disease.

Methods: This research project involves genealogic research including examination of pre-Confederation census data, family records developed by Dr. J. Mannion on how Newfoundland was peopled, and more detailed family interviews.

Results: Pending. Research is ongoing and the discovery of a connection between families remains a high priority but not a certainty.

Conclusions: None at this time.


M. Héroux (1); I. Janssen (1,2); M. Lam (1); D. Lee (3); J. R. Hebert (4); X. Sui (3); S. N. Blair (3,4)

Author References

  1. Department of Community Health Epidemiology, Queen’s University, Kingston, Ontario
  2. School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario
  3. Department of Exercise Science, University of South Carolina, Columbia, South Carolina, US
  4. Department of Epidemiology and Biostatistics, University of South Carolina, South Carolina, US

Dietary patterns and the risk of diabetes mellitus and mortality: impact of cardiorespiratory fitness

Background: Dietary patterns can predict morbidity and mortality risk. Cardiorespiratory fitness may have protective effects; however, its role has been poorly assessed.

Purpose: To assess the relation between dietary patterns, diabetes mellitus and all-cause mortality while controlling for fitness.

Design: Prospective cohort study.

Methods: A clinical exam and three-day diet record was completed by 13 621 adult participants. Diabetes mellitus was assessed at baseline and participants were followed for mortality. Reduced rank regression (RRR) was used to identify dietary patterns that predicted cholesterol, triglyceride, glucose, blood pressure, uric acid, white blood cell and body mass index (BMI) values. Dietary pattern scores were used to predict diabetes mellitus and all-cause mortality.

Results: One primary dietary pattern emerged that was characterized by a higher consumption of meat, potato products, non-whole grains and added fat, and a smaller consumption of non-citrus fruits. Before controlling for fitness, the odds ratio for diabetes mellitus and hazard ratio for all-cause mortality in the fifth versus first quintile of the dietary pattern score were 2.55 (95% confidence interval [CI]: 1.81 to 3.58) and 1.40 (95% CI: 1.02 to 1.91), respectively. These risk estimates were reduced by 51.6% and 55.0%, respectively, after controlling for fitness.

Conclusion: The relation of diet with morbidity and mortality is largely confounded by fitness.


K. M. Hohenadel, G. R. Bauer

Author References

  1. Department of Epidemiology and Biostatics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario

Predicting short interpregnancy intervals in women from underserved populations in London, Ontario

Background: Becoming pregnant within six months of a previous birth is strongly associated with several adverse perinatal and maternal outcomes including preterm birth, low birth weight and small for gestational age. It has been suggested that short interpregnancy intervals may be more common in underserved populations and that the health outcomes are more severe.

Purpose: To develop a model to predict which women are at greatest risk of experiencing a short interpregnancy interval.

Study Design: Retrospective case-control study using variables collected from medical records and auxiliary demographic information from the London InterCommunity Health Centre in London, Ontario.

Methods: Logistic regression will be used to develop a multivariable predictive model with five to seven key risk factors. To ensure maximum clinical usability, a predictive nomogram will be constructed to determine outcome probability.

Results: Pending. The results are currently being analyzed.

Conclusions: The ability to predict short interpregnancy intervals may improve the health status of women at high risk of experiencing a short interpregnancy interval by enhancing the capacity of prenatal clinics to increase preventative care, including providing special attention to nutritional depletion, which is a possible cause of negative health outcomes resulting from short interpregnancy intervals.


Q. Huynh (1); W. Pickett (1,2)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Emergency Medicine, Kingston General Hospital, Kingston, Ontario

Independent and combined effects of tobacco and cannabis on psychosomatic health of Canadian youth

Background: Tobacco and cannabis are drugs commonly used by youth, and are preventable causes of morbidity and mortality. Use of these substances during adolescence is a precursor for unhealthy personal and social lifestyles during adulthood.

Purpose: 1) To profile the prevalence of tobacco and cannabis use among Canadian youth, and 2) to examine associations and possible interactions between measures of substance use and impaired psychosomatic health during adolescence.

Methods: We conducted a secondary analysis of the 2005/2006 Canadian Health Behaviour in School-aged Children (HBSC) Survey. The study sample included 4 324 grade 9 and 10 students. All measures were self-reported. Descriptive analyses and cross-tabulations were used to profile the use of tobacco and cannabis and their associations with impaired health.

Results: By grades 9 and 10, one third of Canadian youth has used tobacco and the same fraction of young people has used cannabis. Tobacco and cannabis use are associated with acute morbidity, although their combined use did not have synergistic effects.

Conclusions: These data document effects of tobacco and cannabis on acute health among adolescents, and as such, informs the content and delivery of intervention programs and the next generation of substance control strategies.


J.-H. Jang (1,2); M. Cotterchio (1,2); D. Daftary (2); S. Gallinger (3,4); B. Bapat (4); N. Lindor (5); N. Monga (2); M.Aronson (6)

Author References

  1. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  2. Population Studies and Surveillance, Cancer Care Ontario, Toronto, Ontario
  3. University Health Network, Toronto, Ontario
  4. Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario
  5. Medical Genetics, Mayo Clinic, Rochester, Minnesota, US
  6. Dr. Zane Cohen Digestive Disease Clinical Research Centre, Mount Sinai Hospital, Toronto, Ontario

Association between double primary endometrial-colorectal cancers and family history of cancer, participant characteristics and underlying molecular features

Background: The occurrence of double primary (DP) endometrial-colorectal cancers is rare, and consequently few studies have described subject factors associated with DP cancers.

Purpose: To investigate dietary, personal history, family history, and biological factors associated with DP endometrial-colorectal cancer.

Study Design: Case-control; single colorectal cancer (CRC) cases versus DP (CRC and endometrial) cases.

Methods: Data from 22 DP cancer cases and 100 single primary CRC cases, recruited as part of the Ontario and Mayo sites of the Colon Cooperative Family Registry, were analyzed. The Wilcoxon rank-sum test was conducted to compare the age of CRC diagnosis between DP and single primary cases. Exact logistic regression was conducted to obtain odds ratio (OR) and age-adjusted OR (AOR) estimates.

Results: The average age of CRC diagnosis for DP cases was significantly younger (53 years) than for single primary cases (59 years) (p < .05). First- or second-degree family history of endometrial cancer was significantly associated with DP cancer risk (OR = 4.6, 95% confidence interval [CI]: 1.3 to 16.6); however, this association was no longer significant after age-adjustment.

Conclusion: Family history of endometrial cancer may be an important factor to consider when evaluating the risk of primary CRC among women diagnosed with endometrial cancer.


A. G. Javan (1,2); C. Bajdik (1,3)

Author References

  1. Cancer Control Research, BC Cancer Agency, Vancouver, British Columbia
  2. Interdisciplinary Oncology Program, University of British Columbia, Vancouver, British Columbia
  3. School of Population and Public Health, University of British Columbia, Vancouver, British Columbia

Sunlight and lung cancer survival in British Columbia

Background: Lung cancer is the deadliest form of cancer in the world. Recent reports indicate that patients who are diagnosed and treated, especially with surgery, during sunny periods have better survival rates.

Hypothesis: Sunlight exposure affects the length of lung cancer patients’ survival if the disease is diagnosed or treated during a sunny period.

Purpose: To provide evidence that sunlight improves the effectiveness of lung cancer treatment.

Study Design: A population-based retrospective study.

Methods: We will examine patients diagnosed with lung cancer during 1996–2005 and referred to the British Columbia Cancer Agency (BCCA) for treatment. Analyses will adjust for patient factors (i.e. age and gender), disease characteristics (i.e. stage and cell histology) and treatment information (i.e. geographic location and surgery, radiation therapy and chemotherapy use). Data from BCCA computerized medical charts will be linked with observations from the British Columbia weather service. A current pilot/feasibility study is using 30 patient records to determine the patient, cancer diagnosis, treatment and weather data that is available and can be modelled in the main study.

Results: Pending. Results of the pilot study, and implications for the main study, will be presented at the conference.


D. Joshi, J. Liu

Author References

  1. Department of Community Health Sciences, Brock University, St. Catharines, Ontario

Comparison of non-HDL cholesterol and waist circumference versus triglyceride levels and waist circumference in predicting coronary heart disease risk

Background: Dyslipidemia is a major cause of coronary heart disease (CHD). The combination of triglycerides (TG) and waist circumference (WC) may be used to predict CHD risk; however, considering the known limitations of TG, non–high-density lipoprotein (non-HDL) cholesterol and WC model may be a better predictor of CHD.

Purpose: To determine if combined non-HDL cholesterol and WC is equivalent or better than combined TG and WC in predicting risk of CHD.

Methods: The analysis included data from 3 196 individuals from the Framingham Heart Offspring Study, aged 40 years plus, with no missing information on key variables, who had fasted overnight for 9 hours or more. Receiver operating characteristic (ROC) area under the curve (AUC) was used to compare the predictive ability of both models.

Results: The ROC AUC associated with non-HDL cholesterol and WC and with TG and WC were 0.6428 (95% confidence interval [CI]: 0.6183 to 0.6673) and 0.6299 (95% CI: 0.6049 to 0.6548) respectively. The difference in the ROC AUC was 1.29% (p = 0.10).

Conclusions: The results suggest that non-HDL cholesterol and WC may be superior at predicting CHD compared to TG and WC.


N. Khobzi (1); G. R. Bauer (1); R. Hammond (2); M. Kaay (3); R. Raj (4); K. Scanlon (5); A. Travers (4)

Author References

  1. Department of Epidemiology and Biostatics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario
  2. Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia
  3. Centre for Addiction and Mental Health, Toronto, Ontario
  4. Sherbourne Health Centre, Toronto, Ontario
  5. The 519 Church Street Community Centre, Toronto, Ontario

The prevalence and predictors of depression in Ontario’s trans communities: doctoral research in progress

Background: “Trans” is an umbrella term used to incorporate people of various gender identifications, including those who identify as transgendered or transsexual. This research involves independent work that expands on the Trans PULSE Project, a community-based research initiative. Depression is understudied in trans communities and reliable estimates are sparse. Disproportionately high prevalence rates of depression, ranging from 8% to 62% have, however, been documented.

Purpose: To determine the prevalence and predictors of depression in Ontario’s trans communities.

Study Design: This study is cross-sectional and adheres to the tenets of community-based epidemiology. Trans Ontarians aged 14 years plus (n = 1 000) will be recruited using respondent-driven sampling (RDS), a probability-based method designed for the recruitment of “hidden populations” via social networks.

Methods: Data collection will begin mid-February. Depression will be measured using the Center for Epidemiologic Studies Depression Scale (CES-D). The following predictors will be examined: age, childhood sexual and physical abuse, hormone use, socioeconomic status, social support, transphobia, racial/ethnic discrimination, and chronic health issues. RDSAT, a software package capable of analyzing RDS datasets, will be employed as it provides means for controlling bias resulting from the network-based sampling method. Weighted bivariate and multivariable analyses will be carried out using SAS version 9.2.

Results: Pending.


A. K. Kirkwood; T. J. Wade

Author References

  1. Department of Community Health Sciences, Brock University, St. Catharines, Ontario

Perceived stress, self-esteem and smoking among adolescents

Background: A risky behaviour often initiated during adolescence is smoking. Adolescents may use smoking to cope with stress. Self-esteem may moderate the relationship between stress and level of smoking.

Purpose: To examine whether adolescent smoking is predicted by stress and self-esteem, and whether self-esteem can moderate the relationship between stress and level of smoking (i.e. non-smoker, experimental, or regular).

Study Design: A secondary analysis of the Canadian Community Health Survey cycles 1.1, 2.1 and 3.1.

Methods: A multinomial logistic regression compared the levels of stress and self-esteem for regular and experimental smokers to non-smoking adolescents, while adjusting for gender, household income, province, and survey cycle.

Results: Higher stress was associated with regular smoking (OR=1.57, 95% CI=1.31, 1.87, P<.0001) and experimental smoking (OR=1.37, 95% CI=1.20, 1.55 P<.000). Adolescents with higher self-esteem were less likely to be regular smokers (OR=.91, 95% CI=.86, .96 P<.000) but not experimental smokers (OR=1.01, 95% CI=.97, 1.05, P=.62). Self-esteem did not moderate the relationship between stress and level of smoking.

Conclusion: Results suggest that health practitioners and educators need to consider stress management and self-esteem issues in a smoking prevention curriculum. Researchers need to investigate the influence of other sociobehavioural factors that may affect the relationship between stress and level of smoking.


A. K. Kirkwood

Author References

  1. Department of Community Health Sciences, Brock University, St. Catharines, Ontario

Outdoor smoking policy and university student smoking

Background: Tobacco use is common among young adults. The presence of strong campus non-smoking policies, including outdoor smoking restrictions, may decrease the prevalence of tobacco use on campus.

Purpose: To examine whether students’ perceptions of the presence of an outdoor smoking policy and the actual strength of such a policy at universities predicts a decrease in smoking from time of school enrolment to the time of study.

Study Design: A secondary data analysis of The Prevalence Study survey conducted on university campuses.

Methods: Self-reported measures included change in smoking status (decrease, no change or increase); perceived knowledge, compliance and type of outdoor smoking restriction; and age, sex and year of study. A researcher-generated data set was used to measure strength of the policy. An ascending ordinal logistic regression for change in smoking status was employed.

Results: Compliance with smoking restrictions was related to the greater odds of decreased smoking. Students were at greater odds of decreasing their smoking if there was a strong non-smoking policy or if they perceived a municipal non-smoking policy.

Conclusion: Since compliance to the non-smoking policies predicted decreased smoking, greater enforcement and stronger policies are recommended. Future research should examine the effectiveness of implementing stronger smoking policies on campuses


G. Ko (1); H. Stuart (1,2,3,4)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Psychiatry, Queen’s University, Kingston, Ontario
  3. School of Rehabilitation Therapy, Queen’s University, Kingston, Ontario
  4. Stigma and Mental Disorders Scientific Section, World Psychiatric Association, Geneva, Switzerland

An international comparison of mental illness stigma

Background: Mental health stigma affects the quality of life of people with mental disorders and creates a barrier to their rehabilitation. International comparisons have been conducted in hopes of gaining insight into this issue. Unfortunately, the little research conducted has compared only a small number of countries using various measures.

Purpose: (1) To complete a cross-cultural analysis of mental health stigma in 26 countries. (2) To explore whether participation in religious organizations, negative social stereotypes pertaining to workforce participation, and country income category may account for these variations.

Study Design: Cross-sectional study.

Methods: We undertook a secondary analysis of the 2000 World Values Survey to assess social distance, our proxy measure of stigma. Social distance is the percentage of people who said they would not like to live in a neighbourhood with emotionally unstable individuals.

Results: Social distance differed by country (Range = 5%-89%). Respondents who belonged to a religious organization expressed less social distance (OR = 0.800, 95% CI = 0.762-0.840), while respondents with negative social stereotypes expressed greater social distance (OR =1.076, 95% CI = 1.026-1.128). Respondents living in low income nations expressed lower social distance (OR=1.802, 95% CI = 1.690-1.921).

Conclusion: Stigma varies by country. These differences may be accounted for by religious views, social stereotypes or the income of a country. More research should be conducted to determine the reason for this difference.


A. Krupoves (1); E. G. Seidman (2); C. Deslandres (2); V. Bucionis (2); D. K. Amre (1,3)

Author References

  1. Research Centre, CHU Sainte-Justine, Montréal, Quebec
  2. Research Institute, McGill University Health Centre, Montréal, Quebec
  3. Department of Pediatrics, University of Montréal, Montréal, Quebec

Response to corticosteroid therapy in pediatric Crohn’s disease patients

Background: Corticosteroids (CS) are widely used to induce remission in Crohn’s disease (CD). CS resistance and dependence are associated with increased surgical intervention and with side-effects, an important concern with children.

Purpose: 1) To assess the outcomes of CS therapy in children diagnosed with CD; and 2) to investigate the potential predictors of CS responsiveness.

Study Design and Methods: The retrospective cohort included patients with CD who received first CS course at a pediatric gastroenterology clinic in Montréal; clinical and socio-demographic information was abstracted from medical records. The immediate response was assessed on the 30th day of CS therapy. CS dependency was defined as a clinical relapse that occurred during tapering of CS or shortly after discontinuing CS treatment. We used logistic regression to identify potential predictors of CS response.

Results: Of 195 patients, 13 (6.67%) were resistant to CS and 72 (39.56%) of 182 initial responders became dependent later. Girls were more likely not to respond (odds ratio [OR] = 3.36, 95% confidence interval [CI]: 0.99 to 1.31, p = .051). CS-dependent patients had earlier CD onset than responders (OR = 0.85, 95% CI: 0.77 to 0.94, p = .002).

Conclusion: Whereas few children were non-responsive to CS, a high proportion became CS dependent. Girls and children with earlier onset appear to be more susceptible.


A. Kukaswadia (1); W. Craig (2); I. Janssen (1,3); W. Pickett (1,4)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Psychology, Queen’s University, Kingston, Ontario
  3. School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario
  4. Clinical Research Centre, Kingston General Hospital, Kingston, Ontario

Bullying involvement as a mediator of weapon-carrying in obese youth

Background: Childhood obesity has been recently linked with increased risks of interpersonal violence. Whether this association extends to outcomes such as weapon carrying remains unknown.

Purpose: To study the relationship between adiposity status and risks for weapon carrying in Canadian school children, and whether this relationship is mediated by physical or relational bullying (both perpetration and victimization).

Study Design: A cross-sectional analysis of the health experiences of 7 877 Canadian children (11 to 15 years old) using the 2006 “Health Behaviour in School-aged Children” survey.

Methods: Focal relationships were evaluated using multi-level logistic regression that accounted for clustering at the school level. A series of four etiological models were developed. Sobel’s test was used to determine whether bullying, either via perpetration or victimization, was a mediator.

Results: Overweight (odds ratio [OR] = 1.45, 95% confidence interval [CI]: 1.04 to 2.02) and obese boys (OR = 2.19, 95% CI: 1.43 to 3.35) reported higher rates of weapon carrying relative to normal-weight boys. No evidence of this relationship was found among girls. Among obese boys, there was partial mediation of this relationship by physical and relational bullying, either as perpetrators or as victims.

Conclusions: Overweight and obese boys aged 11 to 15 years are more likely to carrying weapons for defensive purposes due to bullying.


A. Lanes, H. Tamim

Author References

  1. The School of Kinesiology and Health Science, York University, Toronto, Ontario

Prevalence and characteristics of postpartum depression among Canadian women

Background: Few studies assess the prevalence and predictors of postpartum depression (PPD) across Canadian provinces and territories.

Purpose: To determine the national prevalence and predictors of PPD among Canadian women.

Study Design: A secondary analysis based on the Maternity Experience Survey (MES) will be performed. MES targets women 15 years of age and above who had a live birth within any Canadian province between February 2006 and May 2006 or within any Canadian territory between November 2005 and February 2006.

Methods: PPD will be measured using the Edinburgh Postnatal Depression Scale. A variety of factors will be considered including variables that assess socioeconomic status, demographic factors, maternal characteristics, mother’s perceived health, pregnancy related factors, delivery related factors, and postpartum characteristics. Multivariate logistic regression modelling will be carried out, and bootstrapping to account for the complex sampling design will be performed.

Results: Pending. This project is currently in the development process.

Conclusions: The results will allow for accurate measures to be taken in order to guard against the known predictors of PPD and the allocation of sufficient resources in regions with greater rates of disease.


A. Langley (1); C. Graham (2); K. Aronson (1)

Author References

  1. Department of Community Health and Epidemiology, Queens University, Kingston, Ontario
  2. Department of Anatomy and Cell Biology, Queens University, Kingston, Ontario

Hormones and melatonin in breast cancer risk

Background: Melatonin, a hormone secreted by the pineal gland according to the light-dark cycle, has many established anti-cancer properties. Melatonin secretion is greatest at night during darkness, and exposure to light at night suppresses this secretion, leading to lower circulating melatonin levels. Increased breast cancer risks have been observed for shift workers, believed to be due to suppressed melatonin levels. There are several proposed mechanisms for melatonin’s anti-cancer actions, including suppression of sex hormone levels and signalling pathways.

Purpose: This study will explore melatonin’s regulation of sex hormones by examining the association between melatonin level and sex hormone (estradiol, estrone, progesterone and prolactin) concentrations among rotating shift work nurses at Kingston General Hospital.

Study Design and Methods: Data will be analyzed from a longitudinal study of 110 premenopausal shift work nurses who have already completed a questionnaire and provided blood and urine samples. Melatonin levels will be measured in urine samples and sex hormone concentrations in blood samples, and these levels will be treated as continuous variables for analysis. Linear regression will be used to examine bivariate associations between melatonin and each of the sex hormones and to develop multivariable models adjusting for important covariates.


J. Lapointe (1,2); B. Abdous (1,3); S. Camdem (1); K. Bouchard (1); J. Simard (3,4); M. Dorval (1,2,5)

Author References

  1. Unité de recherche en santé des populations (URESP), Centre hospitalier affilié universitaire de Québec (CHA), Québec, Quebec
  2. Faculté de pharmacie, Université Laval, Québec, Quebec
  3. Faculté de médecine, Université Laval, Québec, Quebec
  4. Laboratoire de génomique du cancer, Centre de recherche du CHUQ (CRCHUL), Québec, Quebec
  5. Centre des maladies du sein Deschênes-Fabia, Hôpital du Saint-Sacrement, Québec, Quebec

Family cluster effect on psychosocial variables in families at high risk for hereditary breast or ovarian cancer

Purpose: Family cluster effect refers to the similarity in responses from individuals recruited in a given family compared to those of individuals from different families. We have investigated the extent of family cluster effect in psychosocial variables among individuals at high risk for hereditary breast and ovarian cancer undergoing BRCA1/2 testing.

Methods: As part of the INHERIT BRCAs (Interdisciplinary Health Research International Team on Breast Cancer susceptibility) research program, 656 French Canadian women (n = 552) and men (n = 104), from 140 families underwent BRCA1/2 testing between 1998 and 2004 and completed a self-reported questionnaire about a wide range of psychological and behavioural issues. The family cluster effect on 31 variables was assessed using the intraclass correlation coefficient as computed from multilevel random-effect models.

Results: Overall, mean intraclass correlation coefficient value was 0.102. It varied between 0 for clinical prostate exam in the previous 12 months and 0.256 for knowledge about genetic testing. The majority of variables, 21 out of the 31, demonstrated a significant family cluster effect.

Conclusions: Our results support the presence of family cluster effect when studying psychosocial aspects of cancer genetic testing. Consideration of this effect is important in the choice of statistical methods and sample size calculations.


P. Lau (1); J. L. Chin (2); S. P. Pautler (2); H. Razvi (1); J. I. Izawa (2)

Author References

  1. Department of Surgery, Division of Urology, University of Western Ontario, London, Ontario
  2. Departments of Surgery and Oncology, Divisions of Urology and Surgical Oncology, Schulich School of Dentistry, University of Western Ontario, London, Ontario

NMP22 is predictive of recurrence in high risk superficial bladder cancer patients

Background: The NMP22 assay has been shown to have greater sensitivity for the diagnosis and detection of urothelial carcinoma (UC) of the bladder over that of urine cytology.

Purpose: To assess the use of NMP22 to predict which high risk superficial UC patients will have recurrence, progression or disease related death.

Study Design: Cohort, prospective.

Methods: One hundred patients with high risk superficial UC were enrolled. During surveillance, urine was collected for cytology and NMP22 testing. Patients were followed for at least six months. Retrospective chart review was undertaken to collect data on tumour history, tumour characteristics, disease recurrences, progression and death. Kaplan-Meier analyses were performed to determine the significance between NMP22 positive and negative patients in terms of recurrence-free, progression-free and overall survival.

Results: Of 94 eligible patients, 15 were NMP22-positive and 79 NMP22-negative. Baseline characteristics between the two groups were not significantly different in terms of patient characteristics, tumour history or prior intravesical therapies. Mean recurrence-free survival time was significantly lower in the NMP22-positive group (p = .038); however, mean progression-free and overall survival were not significantly different between the two groups (p =.297 and .519, respectively).

Conclusion: NMP22 appears to have predictive value for future tumour recurrences, but not for progression or survival in patients with high risk superficial UC.


R. Lewis (1,2); D. Krewski (1,2); Y. Chen (2)

Author References

  1. R. Samuel McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario
  2. Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario

An analysis of the American Cancer Society cohort linking specific chemical constituents of air pollution to mortality

Background: Air pollution is an important determinant of health. The World Health Organization estimates that air pollution is responsible for nearly 2% of all deaths globally.

Purpose: To determine the specific components of air pollution linked to increased risk of mortality in the general population. Since the emission of a single air pollutant is unlikely, combinations of pollutants must be investigated.

Study Design: A cohort study design.

Methods: The health outcomes investigated include mortality from cardiopulmonary conditions, lung cancer and all causes combined. Air pollution data from various metropolitan regions in the U.S. were linked to the outcomes of individuals in these areas. Characteristics of individuals that may affect the relationship between air pollution and mortality (e.g. age, sex, smoking history) were obtained from the American Cancer Society Cancer Prevention Study II cohort. Nearly 1.2 million adults were enrolled in this study in 1982 and have been followed up on an on-going basis.

Results/Conclusions: This study suggests that sulfates and, more broadly, fine particulate matter may be the most important contributors to excess risk of all-cause, cardiopulmonary and lung cancer mortality. These relationships were statistically significant at the 95% level of confidence, based on single and multiple pollutant Cox proportional hazards models.


S. R. Luca, S. Murtha

Author References

  1. Department of Psychology, York University, Toronto, Ontario

Effects of cross-modal cueing on spatial attention

Background: Attention facilitates the processing of information on a variety of tasks. Determining the cognitive factors that enhance selective attention may help guide cognitive rehabilitation programs designed to help patients with problems focusing attention (e.g. patients with Alzheimer’s disease). One such cognitive factor may be the influence of auditory cues.

Purpose: To assess the influence of auditory cues (alerting, orienting) on the performance of a visual spatial attention task in healthy young adults.

Study Design: Randomized controlled trial.

Methods: Students between the ages of 17 and 25 from York University were recruited to participate in this study. Novel shapes were presented on each side of a computer screen and participants responded with the upper key if the shape was in the upper quadrant or with the lower key if the shape was in the lower quadrant. Some of the trials were preceded by a tone, while others did not have any cue associated with them. We predict that orienting cues, which direct attention to a specific field, will decrease reaction time more than alerting cues, which act as reminders to keep the focus sustained on a task.

Results: Pending.

Conclusions: None at this time.


J. Macintosh (1,2); K. Lawrance (1,2); J. Liu (1); S. Dupuis (1,2)

Author References

  1. Department of Community Health Sciences, Brock University, St. Catharines, Ontario
  2. Leave The Pack Behind, University of Toronto, Toronto, Ontario

The impact of campus tobacco control policies on marijuana use among Ontario undergraduates

Background: There is increasing evidence that tobacco and marijuana use are concurrent. Additionally, marijuana has similar health risks as tobacco. Tobacco control policies appear to inhibit smoking by dissuading initiation and supporting smokers to quit. Campus tobacco control policies have been shown to reduce tobacco smoking among young adults. A US study suggests tobacco control policies may impact the prevalence of marijuana use.

Purpose: To determine if campus tobacco control policies affect marijuana prevalence.

Study Design: Cross-sectional representative study.

Methods: From a stratified sample of 10 universities, students were invited to complete an on-line survey; 9 140 participants did so.

Results: Complete data were available for 5 775 university students, ages 17 to 24. Campuses with stronger campus tobacco control policies tended to have a lower marijuana prevalence (chi-square [χ2] = 28.937, p < 0.0001). After controlling for socio-demographic characteristics closely associated with marijuana and tobacco, students exposed to a moderate campus tobacco control policy were less likely than students exposed to weak campus tobacco control policy to use marijuana (odds ratio [OR] = 0.664; 95% confidence interval [CI]: 0.538 to 0.818).

Conclusions: Campus tobacco control policies were found to negatively impact marijuana use. This finding suggests that changes in the social norm associated with tobacco may change the social norm associated with marijuana.


N. T. MacLeod (1); R. Sebaldt (1,2,3); E. Pullenayegum (1,3); P. Selby (4,5,6)

Author References

  1. Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario
  2. Department of Medicine, McMaster University, Hamilton, Ontario
  3. The Centre for Evaluation of Medicines, Hamilton, Ontario
  4. Centre for Addiction and Mental Health, Toronto, Ontario
  5. Department of Family and Community Medicine, University of Toronto, Toronto, Ontario
  6. Department of Psychiatry, University of Toronto, Toronto, Ontario

The effectiveness of P-PROMPT CDMS in increasing the delivery of smoking cessation counselling in Ontario

Background: The number one preventable cause of death and disease in Canada is smoking. While effective interventions do exist, most physicians do not actively and consistently deliver smoking cessation treatment. P-PROMPT Chronic Disease Management System (CDMS) is a multi-faceted patient management tool designed to increase systematic delivery of preventive care and CDMSs. It has been proven effective in increasing the delivery of mammographies, pap tests and influenza shots.

Purpose: To determine the effectiveness of P-PROMPT CDMS in increasing the delivery of smoking cessation counselling. The CDMS as an intervention will implement a smoker-identification system to build a target patient registry, present ongoing physician performance audit and feedback, and provide both physician and patient prompts.

Study Design A six-month long cluster randomized controlled trial with a target population of 96 P-PROMPT physician subscribers in Ontario. The unit of randomization will be the primary care practice while the unit of analysis will be the physician.

Methods: Following stratified randomized study arm allocation of primary care practices, only the intervention group will have access to the smoking cessation management component of P-PROMPT CDMS. OHIP billing codes will be used to determine the proportion of smokers counselled by each physician.

Results: Pending

Conclusions: Pending


H. Majeed (1,2); P. S. Wells (1,2); D. A. Coyle (1)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Hematology and Thrombosis Clinic, Ottawa Hospital, Civic Campus, Ottawa, Ontario

Thrombophilia screening for high risk patients in Canada: assessing the risk and cost-effectiveness

Background: Venous thromboembolism (VTE), the formation of blood clots leading to occlusion of vessels, is a significant cause of hospital morbidity and mortality. Thrombophilia, the presence of genetic and biochemical risk factors that increase the likelihood of clotting, has an additive effect with high risk situations (post-surgery or when taking oral estrogen).

Purpose: To quantify the risk of VTE in the aforementioned high risk situations; and 2) to evaluate whether a universal or selective screening program for thrombophilia will be cost effective in Canada.

Methods: A systematic review of the literature will be undertaken (EMBASE, MEDLINE, CINAHL) to assess the risk of VTE associated with thrombophilia for populating the model. A decision analytic approach will be used to evaluate the incremental cost effectiveness ratios (ICER) of screening versus no screening with the primary outcome being number of VTE events prevented. Monte Carlo simulations will be undertaken to evaluate uncertainties with Extra Value of Perfect Information (EVPI) calculations being performed.

Results: Pending. The results of the systematic review will be presented as a narrative summary along with results of the cost-effectiveness analysis and relevant sensitivity analyses.

Conclusion: Pending. Recommendations will be put forward as to whether thrombophilia screening is cost effective in Canada for high risk patients.


T. Matukala Nkosi (1); M. C. Rousseau (1,2); M. E. Parent (1,2); J. Siemiatycki (1,3)

Author References

  1. Department of Epidemiology and Biostatistics, University of Montréal, Montréal, Quebec
  2. INRS-Institut Armand-Frappier, Laval, Quebec
  3. CHUM Research Centre, Montréal, Quebec

Studying socioeconomic status and lung cancer risk: how important is the modelling of smoking?

Background: Studies suggested an increased risk of lung cancer with a low socioeconomic status (SES). This relationship varies according to the availability of information on smoking, etc.

Purpose: To assess the relationship between SES and risk of lung cancer.

Methods: Using data from a Montréal case-control study, we measured SES using three financial situation indicators: self-reported income, census-based income and residential value index. Associations between SES and risk of lung cancer were estimated using logistic regression. Akaike's Information Criterion was used to compare the fit between different models.

Results: Each financial situation indicator was associated with lung cancer before adjusting for smoking and these effects disappeared after adjusting for smoking. For census-based income, the SES-lung cancer odds ratio were OR = 0.46 (95% confidence interval [CI]: 0.25 to 0.83) when adjusted for smoking status; OR = 0.59 (95% CI: 0.32 to 1.10) when adjusted for pack-years; and OR = 0.85 (95% CI: 0.45 to 1.63) when adjusting with the three-variable model. With the most detailed smoking adjustment, none of the financial situation indicators was associated with lung cancer or led to an improved model fit.

Conclusion: Regardless of which indicators of financial situation, SES was not associated with the risk of lung cancer when properly adjusting for smoking.


L. Mayo-Bruinsma, Y. Chen

Author References

  1. Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario

Perception of insufficient milk supply associated with shorter duration of exclusive breastfeeding

Background: Despite recommendations that exclusive breastfeeding should continue for at least 4 months, many women stop breastfeeding sooner. Self-efficacy and maternal confidence are associated with breastfeeding duration in small intervention studies. Low self-efficacy and low-confidence contribute to the perception of insufficient milk.

Purpose: To determine whether perception of insufficient milk is associated with failure to breastfeed for at least 4 months.

Study Design: Cross-sectional Canadian national survey conducted in 2005. A total of 5 058 women between 20 and 49 years of age who gave birth in the previous five years were included in the analysis.

Methods: A log-binomial regression model was used to examine the association between breastfeeding for 4 months or more and perceived insufficient milk supply.

Results: Perceived insufficient milk supply was the most common reason for breastfeeding cessation. The proportion of women who breastfed for a minimum of four months was much lower among participants who perceived insufficient milk (32%), compared with those who stopped for another reason (57%). The prevalence ratio for women who perceived insufficient milk was 0.58 (95% confidence interval [CI]: 0.53 to 0.64) after adjustment for confounders.

Conclusions: Women who perceived insufficient milk were more likely to stop breastfeeding earlier. Interventions stressing the adequacy of milk supply may increase the duration of breastfeeding.


L. Mayo-Bruinsma (1); W. E. Hogg (1,2,3,4); S. Dahrouge (2,3)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. C.T. Lamont Primary Health Care Research Centre, Élisabeth Bruyère Research Institute, Ottawa, Ontario
  3. Institute of Population Health, University of Ottawa, Ottawa, Ontario
  4. Department of Family Medicine, University of Ottawa, Ottawa, Ontario

Family-centred care delivery: comparing models of primary-care service delivery in Ontario

Background: Primary care is critical to the health system in Canada. Ontario has primary-care service delivery models in which providers are remunerated primarily by salary, capitation, fee-for-service, and a blended formula. Evaluating primary care delivery methods is crucial to the continuing evolution of primary care in Ontario. Family-centred care (FCC) has attracted considerable attention in recent years. FCC is closely related to patient-centred care and focuses on the consideration of the family in planning/implementing care. FCC is associated with increased patient satisfaction.

Purpose: 1) To determine whether one model of primary care delivery is more effective at providing FCC than others, and 2) to determine which organizational characteristics of primary care practices are associated with better FCC.

Study Design: Cross-sectional study

Methods: In 2005–2006, 5 361 patients and 363 providers from 137 practices that used one of the four remuneration models were surveyed. FCC was measured in the patient and provider surveys. Details on organization and governance of practices and demographic details for patients were collected. Data will be analysed using multi-level statistical analysis.

Results: Pending

Conclusions: Pending. Results could significantly affect health care policy development to generate more effective FCC and improve patient satisfaction with the health system.


M. McKeown (1); M. Stewart (1,2); A. Thind (1,2)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Centre for Studies in Family Medicine, University of Western Ontario, London, Ontario

Operationalization of episodes of care in electronic family medicine: what is the effect of different “time-windows”?

Background: Episodes of care, a concept of care utilization and health management, are physician visit(s) for a specific health condition separated by “time windows,” or breaks in condition-specific contact with the physician. Research that uses this concept provides contradicting episode definitions and little justification.

Purpose: To determine the effect of different lengths of time windows on episodes of care, exemplified with back pain.

Study Design: A longitudinal, observational study using data from the Deliver Primary Health Care Information project, an EMR database.

Methods: Back pain episodes of care were defined as series of physician visits with back pain diagnoses, preceded and followed by time windows lacking such diagnoses. A sensitivity analysis was conducted with four different time windows—30, 60, 90, and 120 days—among 464 back pain patients.

Results: With a 30-day time window there were 653 episodes, with a mean length of 5.5 days and 1.28 visits; with a 60-day time window, 456 episodes, 15 days and 1.53 visits; with a 90-day time window, 339 episodes, 21.3 days and 1.57 visits; with a 120-day time window, 256 episodes, 19 days and 1.47 visits.

Conclusions: A sensitivity analysis of episode definition should be included in research using this concept given the variability in study population with different definitions.


M. McPherson (1); W. Pickett (1,2)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Emergency Medicine, Queen’s University, Kingston, Ontario

Characteristics of martial art injuries in a defined Canadian population

Background: Martial arts have emerged as a common activity in Canadian populations. However, few studies have investigated the occurrence of martial arts injuries in a defined population.

Purpose: 1) To investigate the magnitude and characteristics of martial arts injuries; and 2) to suggest potential opportunities for prevention.

Study Design: Descriptive analysis of emergency department injury surveillance data (1996–2006) from the Kingston sites of the Canadian Hospital Injury and Prevention Program.

Methods: Incidence rates were calculated using census data as denominators. Patterns of injury were profiled according to style of martial art, and the nature, mechanism and anatomical site of injury. 920 cases were identified.

Results: The annual age-standardized incidence rate was 6.9 per 10 000 males and 3.1 per 10 000 females. Injuries were most frequently reported in karate (33%) and taekwondo (14%). The most common mechanisms of injury were falls, throws and jumps (33%). Fractures (20%) were the most frequently reported type of injury and the lower limb was the most common site of injury (41%).

Conclusions: Martial art injuries were found to be an important source of morbidity within the population, and the characteristics of these injuries provide a foundation for potential safety interventions to limit these injuries in the future.


M. McPherson (1); I. Janssen (1,2); K. J. Aronson (1)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario

Physical activity and melatonin among rotating shift nurses

Background: The International Agency for Research on Cancer recently classified shift work as a probable carcinogen, and fluctuations in melatonin levels have been proposed as an intermediate factor in the pathway to cancer. The role of physical activity and sedentary behaviour on this relationship has not been well established, and if it is influential it could provide an important method of minimizing these hormonal fluctuations in shift workers.

Purpose: To determine the role of physical activity and sedentary behaviour on urinary melatonin levels among rotating shift workers.

Study Design and Methods: A cross-sectional study is being conducted of 124 healthy female nurses working at Kingston General Hospital who were recruited over a two-year period. Participants complete a questionnaire on demographic factors, menopausal status, lifestyle habits and work history. Each nurse takes part in two data collection periods in summer and winter and within each season on both a day and a night shift. Participants are asked to wear a pedometer during each shift to measure acute physical activity levels and to complete a diary outlining their physical activity for the previous 48 hours and for a month prior to enrollment. Melatonin levels will be determined from urine concentrations of 6-sulfatoxymelatonin, a metabolite of serum melatonin.

Results and Conclusions: Pending.


Q. Miao (1); D. Chen (2); K. J. Aronson (1)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Geography, Queen’s University, Kingston, Ontario

Traffic exposure: a comparison of survey, biomarker and geographic information system methods

Background: Exposure to traffic in most epidemiologic studies has been evaluated by asking study participants to complete questionnaires. Geographic information systems (GIS) could be used to measure traffic density, but it is not clear how this method relates to personal exposure to traffic, nor what the relationship is between these methods. This can be assessed by comparing these methods to 1-hydroxypyrene (1-OHP), a biomarker of polycyclic aromatic hydrocarbon (PAH) exposure.

Purpose: To assess if 1-OHP concentration in urine is correlated with self-report and GIS-based methods for traffic exposure measurement and to explore the determinants of this biomarker.

Methods: Information collected through questionnaires will be used to assess the exposure to traffic of 250 urban- and 250 rural-dwelling volunteers ages 16-60 in Nanjing, China, and this will be compared to 1-OHP levels in urine and to traffic density data linked through GIS. Multiple regression models will be used to evaluate the determinants of the biomarker.

Results: Pending.


M. Miszkurka (1); L. Goulet (1,2); M.V. Zunzunegui (1,2)

Author References

  1. Département de médecine sociale et préventive, Université de Montréal, Montréal, Quebec
  2. Groupe de recherche interdisciplinaire en santé (GRIS), Université de Montréal, Montréal, Quebec

Depressive symptoms during pregnancy – Identifying the most vulnerable women

Background: Pregnancy carries a high risk of depression for 12% of women, with rates of 41% reported among female immigrants.

Objective: Measure the prevalence of prenatal depression among Canadian-born women and female immigrants by the number of years since immigration and region of birth; Compare their socio-economic situations; Examine the association between immigrant status and prenatal depression.

Procedure: Cross-sectional study.

Method: 5334 femmes women were recruited during prenatal visits at 16-20 weeks of pregnancy, in 4 Montréal hospitals. Depression was measured using the CES-D depression scale. The data were compared using the chi-square test and analyzed using logistic regression.

Results: Prenatal depression is more prevalent among female immigrants (32%) than Canadian-born women (23%). Level of education decreases the association between immigrant status and depression. Family income partially explains prenatal depression in certain groups of female immigrants.

Conclusion: Female immigrants are more greatly affected by prenatal depression than Canadian-born women. Health inequalities persist during the time they reside in Canada. Female minorities are the most vulnerable to depression during pregnancy.


A. Moore-Cox (1); S. Jack (2); H. MacMillan (3)

Author References

  1. Health Research Methodology Graduate Program, McMaster University, Hamilton, Ontario
  2. School of Nursing, McMaster University, Hamilton, Ontario
  3. Psychiatry and Behavioural Neurosciences; Department of Pediatrics, McMaster University, Hamilton, Ontario

The retention strategies study

Background: Participant retention is a challenging but critical component of high quality, valid research. Abused women are a vulnerable population with unique health care needs who are often difficult to retain in research studies. In a randomized controlled trial (RCT) examining the effectiveness of universal screening and referral for reducing subsequent abuse in women exposed to violence, low attrition rates (9%) were recorded between baseline and final data collection.

Purpose: To describe what strategies research staff used that contributed to successful participant retention.

Study Design: A fundamental qualitative descriptive study.

Methods: Of the 14 research staff, 12 consented to participate, and each completed two in-depth, semi-structured interviews. Key themes were identified through conventional content analysis.

Results: Research assistants were professionally and personally committed to the goals of the RCT. They utilized creative approaches to locate participants and were persistent in making regular contact. The most important factors were developing trust between the research assistant and the participant, giving participants control over time and location for meetings, and the use of incremental monetary incentives.

Conclusion: Abused women can be located and interviewed as part of research studies with high retention success by committed research staff who have had extensive support and training.


B. Nguyen (1); J. Gomes (2,3)

Author References

  1. Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario
  2. Health Science Program, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario
  3. R. Samuel McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario

Epigenomic changes in testicular cells from exposure to phthalates

Background: Testicular cancer is the most common malignancy in young men and accounts for 1% to 2% of all malignancies in the male population. It has been associated with risk factors, such as cryptorchidism, environmental and occupational exposures, maternal risk factors and hereditary factors. Testicular cancer consists of a variety of neoplasms in which approximately 95% are testicular germ cell tumours. The remaining 5% originate mostly from Leydig or Sertoli cell tumours. Although the epidemiology has been well established, the etiology is not well understood. Phthalates are industrial plasticizers that are endocrine disruptors, exhibiting anti-androgenic and pro-estrogenic effect. They have been implicated in testicular dysgenesis syndrome which is also believed to be a risk factor for testicular cancer. However, the role of phthalates in testicular carcinogenesis has not been described and remains to be explored.

Purpose: To examine gene promoter-region methylation in testicular cells and assess the relationship between exposure to phthalates and the methylation status of tumour suppressor genes PRSS21, RASSF1A, MGMT and SCGB3A1.

Method: The methylation status of these genes is examined in primary cell cultures of Leydig cells under laboratory conditions.

Results: Pending.

Conclusion: Pending.


M. Noparast (1,2); C. Bajdik (1,3)

Author References

  1. Cancer Control Research, BC Cancer Agency, Vancouver, British Columbia
  2. Interdisciplinary Oncology Program, University of British Columbia, Vancouver, British Columbia
  3. School of Population and Public Health, University of British Columbia, Vancouver, British Columbia

Ethnicity and hematopoietic stem cell transplantation in British Columbia

Background: Ethnic disparities in health care access, use and clinical outcomes occur in Canada. Hematopoietic stem cell transplantation (HSCT) is the accepted treatment for several malignancies, and more than 70% of HSCT candidates require a transplant from someone outside their families. It is suspected that available donors do not represent the population’s ethnic minorities.

Purpose: To determine whether ethnicity is associated with HSCT outcomes in patients with hematologic malignancies.

Study Design: Medical chart review.

Methods: Data related to HSCT patients (age, gender, ethnicity), disease (cancer type and stage, date of diagnosis, comorbidities), treatment (date and type of HSCT) and outcomes (follow-up time and events) will be abstracted from The Leukemia/Bone Marrow Transplant Program of BC database for the period of 1980 to 2009. Descriptive statistics and logistic regression will be used to determine relationships between patient ethnicity and various outcomes. Results will be used to determine specific hypotheses for a subsequent prospective study.

Results: Mean age of patients was 43.5 ± 13.3 years and most of them (60%) were male. 53.6% of the cases underwent autologus transplant and the rest got allogenic or syngenic transplant. The most common underlying disease was multiple myeloma (24%). Patients’ ethnicity was recorded for 1349 patients among whom 40 % were white.

Conclusion: As the ethnicity of more than half of the patients is not determined in BMT registry database, it was not possible to compare the outcome between different ethnic groups. The plan is to determine the missing data by alternative methods


A. Nourissat, I. Bairati, F. Meyer

Author References

  1. Clinical Epidemiology Unit, Laval University Cancer Research Centre, Québec

Predictors of weight loss during radiation therapy in patients with head and neck cancer

Background: The nutritional care of patients with head and neck cancer (HNC) is an important issue in the global therapeutic strategy.

Purpose: To identify predictors of weight loss during radiation therapy (RT) in patients with stage I or II HNC.

Methods: This study was conducted as part of a phase III chemoprevention trial. A total of 540 patients were randomized. Patients were weighed before and after RT. Weight loss during RT was the outcome of interest. The potential predictors evaluated were patients’ characteristics, life habits, tumour and treatment characteristics. Predictors were identified using multiple linear regression.

Results: The mean of weight loss was 2.2 kg (standard deviation = 3.39). Six factors were associated with weight loss. Patients with higher weight before RT (ß = -0.26, p < .001), with dysphagia before RT (ß = -0.18, p < .001), with stage II HNC (ß = -0.17, p < .001), with higher total dose of RT (ß = -0.09, p = .033) and women (ß = -0.10, p = 0.012) experienced considerable weight loss. Patients with laryngeal cancer have less risk of weight loss (ß = 0.16, p < .001). There were no association with life habits, diet and quality of life before RT. The model explained 20.9% of the variance in weight loss.

Conclusion: These results could be useful to clinicians for screening patients requiring particular nutritional attention.


A. Pasricha (1,2); N. Burke (2); J. Bowen (2); K. Campbell (2); N. Assasi (2); R. Goeree (2,3); D. O'Reilly (3)

Author References

  1. Health Research Methodology, McMaster University, Hamilton, Ontario
  2. Programs for Assessment of Technology in Health (PATH) Research Institute, Hamilton, Ontario
  3. Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario

Systematic review of hyperbaric oxygen therapy for the treatment of non-healing diabetic ulcers

Background: Non-healing lower limb ulcers are a major source of morbidity and resource use in individuals with diabetes mellitus. Hyperbaric oxygen therapy (HBOT) may improve oxygen supply to ulcers and improve healing through the inhalation of 100% oxygen at high pressure in a compression chamber.

Purpose: To evaluate the role of HBOT in the management of non-healing lower limb diabetic ulcers.

Study Design: Systematic review.

Methods: Databases searched include MEDLINE, EMBASE, CINAHL, PubMed, Wiley’s Cochrane Library, and Thomson’s Biosis Previews using keywords focusing on “HBOT” and “diabetic ulcers.” Two independent reviewers selected studies based on pre-specified inclusion/exclusion criteria. Quality assessment was completed using the Jadad scale.

Results: A total of 353 articles were identified and data was extracted from 24 publications with the primary outcomes being rate of amputation and wound size reduction. Relative risk of amputation and wound size reduction in terms of mean difference were also abstracted and analyzed through meta-analytic techniques.

Conclusion: Randomized control trial evidence on HBOT is limited and additional trials are needed to ascertain its efficacy in diabetic ulcers. This review contributes to the evidence surrounding chronic care management and costs that are current priorities for the Canadian health care system.


D. Perez, P. Ritvo, C. Ardern (1,3)

Author References

  1. The School of Kinesiology and Health Science, York University, Toronto, Ontario

Perceived safety and walkability: environmental and social effects on the prevalence of physical activity in the Jane–Finch community (Toronto)

Background: Decreased levels of physical activity (PA) and increasing levels of obesity are growing concerns, especially in new immigrant and low socioeconomic status (SES) populations. Walkable neighbourhoods have been shown to facilitate desirable outcomes like increased physical activity (PA) and decreased car use.

Purpose: To evaluate relationships between measures of walkability, psychosocial correlates of PA, perceived danger and PA in a low-SES, high-immigrant population of women residing in the Jane-Finch neighbourhood of Toronto (J-F).

Study Design: A cross-sectional sample of women from J-F completed a 20-minute self-report survey.

Methods: Bivariate analyses and multiple linear regressions were performed to assess the impact of social, environmental and individual factors on the prevalence of PA.

Results: Walkability appears to be significantly correlated with total PA in participants who own or have access to a car, but this finding is not replicated in participants who have no car access, suggesting neighbourhood walkability characteristics are of little relevance when vehicles are not available. Social networking and psychosocial correlates of exercise appear to be consistently associated with total PA.

Conclusion: The relationship between walkability, psychosocial correlates of exercise and total PA in low-SES neighbourhoods appears significant and warrants further investigation.


S. Prasad (1); J. Gomes J (2,3)

Author References

  1. Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario
  2. Health Science Program, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario
  3. R. Samuel McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario

Understanding the etiology and risk factors of testicular cancer

Background: Testicular cancer (TC) is the most common malignancy diagnosed among young men aged 15 to 35 years, and its incidence within many Western countries has risen sharply in the last few decades. Although TC has one of the highest cure rates and its epidemiology is well-defined, the etiology of TC, including the risk factors associated with TC development, remains to be characterized.

Purpose: 1) To examine the interplay between epigenetic factors and exposure to exogenous hormones to better understand the etiology of testicular cancer; 2) to shed light on lifestyle, dietary, occupational and environmental risk factors of testicular cancer, as well as the role of DNA methylation in the etiology of testicular cancer.

Methods: Through a case-control study, information will be collected to explore the risk factors of testicular cancer. The mother of each participant will also be invited to participate in order to determine risk factors during foetal development. Methylation-specific polymerase chain reaction (PCR) will be used on blood and saliva samples collected from cases and controls to determine the methylation status of specific genes of interest.

Conclusion: Pending. The findings of this study will help identify the risk factors and develop strategies for prevention and control of testicular cancer.


S. Prince (1,2); E. Kristjansson (3); K. Russell (4); A. Ali (4); D. Prud’homme (5); M. Tremblay (2); M. Sawada (6)

Author References

  1. Institute of Population Health, University of Ottawa, Ottawa, Ontario
  2. Healthy Active Living and Obesity Research Group, CHEO Research Institute, Children’s Hospital of Eastern Ontario, Ottawa, Ontario
  3. School of Psychology, Faculty of Social Sciences, University of Ottawa, Ottawa, Ontario
  4. Ottawa Public Health, Nepean, Ontario
  5. School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario
  6. Department of Geography, Faculty of Arts, University of Ottawa, Ottawa, Ontario

Built and social environmental determinants of adult physical activity, overweight and obesity in 89 City of Ottawa neighbourhoods

Background: The social and built environments are possible contributors to the development of healthy behaviours such as physical activity (PA); however, there remains a paucity of Canadian research looking at these relationships.

Purpose: To determine the relationships between neighbourhood built and social environments and individual rates of PA and overweight/obesity across 89 Ottawa neighbourhoods.

Design: Cross-sectional study.

Methods: The study is a secondary evaluation of self-reported PA and height, weight and measures of built and social environmental factors across 89 Ottawa neighbourhoods. PA and height and weight were collected from about 4 600 adults using the International Physical Activity Questionnaire from the 2003–2007 samples of the Rapid Risk Factor Surveillance System and from about 5 608 adults using leisure time PA questions of the 2001/03/05/07 Canadian Community Health Survey (CCHS). The built environment data (e.g. parks, bike paths) was collected using the Ottawa Neighbourhood Study and the social environment data (e.g. voting and crime rates, community belonging, neighbourhood socioeconomic status) from the CCHS and the City of Ottawa. Hierarchical linear modelling will be used to explore the multi-level determinants of PA and overweight/obesity.

Results: Pending.

Conclusions: Results will inform current gaps in the literature and recommendations for the design of municipalities and policies to promote PA in adults.


K. Quansah (1); E. Vingilis (1,2); R. E. Mann (3); M. Speechley (1)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Family Medicine, University of Western Ontario, London, Ontario
  3. Social, Prevention and Health Policy Research Department, Centre for Addiction and Mental Health, Toronto, Ontario

The effect of psychotropic medications on the risk of motor vehicle collisions for individuals with symptoms of anxiety and depression

Background: Symptoms of mental illness may increase the risk of motor vehicle collisions (MVCs). Anxiety and depression are among the most prevalent mental illnesses in Canada; psychotropic medications are a frequently prescribed treatment for these symptoms. It is unclear how psychotropic medications affect MVC risk in anxious/depressed populations.

Purpose: To determine if psychotropic medications mediate the risk of MVCs in a population with anxiety and depression symptoms (psychiatric distress).

Study Design: A cross-sectional study of the 2002–2004 and 2006 waves of the Centre for Addiction and Mental Health (CAMH) Monitor data.

Methods: Hierarchical logistic regression analysis was conducted to determine if psychotropic medications act as a mediator. Demographic predictors (age, sex and marital status), psychiatric distress, and psychotropic medications were entered into blocks. Model 1 included two blocks (demographics and psychiatric distress); model 2 had three blocks. Psychotropic medications were added. Demographic predictors acted as control variables (n = 5 862).

Results: The odds of MVCs occurring for individuals with psychiatric distress remained unchanged in the presence or absence of psychotropic medications.

Conclusions: Among a representative sample of Ontario adults, there is no evidence that psychotropic medications mediate MVC risk for individuals with psychiatric distress.


K. Reidel (1); R. Tamblyn (1,2); M. Choinière (3)

Author References

  1. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec
  2. Faculty of Medicine, McGill University, Montréal, Quebec
  3. Centre hospitalier de l'Université de Montréal, Montréal, Quebec

Temporal trends in opioid analgesics for non-cancer pain

Background: Recently there has been a rapid rise in the use of opioid analgesics for chronic pain. While this may be viewed as a positive response to guidelines to improve cancer pain management, there is evidence of unintended effects. A considerable increase in abuse of opioid analgesics has been reported by both law enforcement agencies and medical examiners. One investigation showed a dramatic increase in unintentional poisoning deaths due to opioid analgesics. Further, a staggering 19% of the Danish population reported non-cancer chronic pain, of which 12% reported using opioids even though the effectiveness of opioid analgesics for chronic, non-cancer pain is not supported by literature.

Purpose: To estimate temporal trends in opioid use for non-cancer pain in Quebec.

Study Design: Time series.

Methods: All prescriptions dispensed between 1994 and 2007 for RAMQ-insured persons with no diagnostic or procedural code for cancer in the previous year were retrieved. For each study period day, the proportion of persons with available opioid analgesics and the mean WHO-standardized dose of opioid analgesics per person will be calculated. Time series analysis will be used to examine if use and/or dose of opioids for non-cancer pain in Quebec has increased over time.

Results/Conclusions: Pending. Study in progress.


A. Roy (1); W. R. Avison (1,2,3,5,6); S. E. Evers (7); M. K. Campbell (1,2,4,5,6)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Paediatrics, University of Western Ontario, London, Ontario
  3. Department of Sociology, University of Western Ontario, London, Ontario
  4. Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario
  5. Children’s Health Research Institute, London, Ontario
  6. Lawson Health Research Institute, London Health Sciences Centre, London, Ontario
  7. Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, Ontario

Is zinc a mediator or a moderator of psychosocial stress in a causal model of maternal prenatal depressive symptoms?

Background: Prenatal depression is a significant public health concern.

Purpose: To model associations involving dietary zinc intake, psychosocial stress and baseline socio-demographic factors as they interrelate in the development of depressive symptoms in a cohort of pregnant women.

Hypotheses: 1) Psychosocial stress serves as a partial mediator between baseline socio-demographic factors and zinc intake; and 2) zinc intake serves as a partial mediator between baseline socio-demographic factors and the development of depressive symptoms, and between psychosocial stress and the development of depressive symptoms.

Methods: Data were collected through the Prenatal Health Project. The Center for Epidemiologic Studies Depression Scale was used to assess depressive symptoms. Psychosocial stress was summarized into a standardized composite score. Zinc intake was quantified from food frequency questionnaires and data regarding nutritional supplements use. Analyses employed regression methods. Baron and Kenny’s procedures were used to test for mediation. Evidence for moderation was investigated by adding interaction terms.

Results and Conclusions: Unmarried status, lower education, unemployment, not having other children, higher stress and lower zinc intake were associated with increased depressive symptoms. Social disadvantage, higher stress and lower zinc intake were associated with increased depressive symptoms. Evidence was not in favour of the mediation hypotheses, but instead showed that zinc intake was a moderator in the association between stress and depressive symptoms.


J. A. Ryan (1); M. Casapía (2); H. Silva (3); E. Aguilar (3); E. Rahme (1,4); A. J. Gagnon (5); A. R. Manges (1); T. W. Gyorkos (1,4)

Author References

  1. Department of Epidemiology and Biostatistics, McGill University, Montréal, Quebec
  2. Asociación Civil Selva Amazónica (ACSA); Universidad Nacional de la Amazonía Peruana (UNAP), Iquitos, Peru
  3. Hospital Apoyo Iquitos, Iquitos, Peru
  4. Division of Clinical Epidemiology, McGill University Health Centre, Montréal, Quebec
  5. Department of Obstetrics and Gynecology; School of Nursing, McGill University, Montréal, Quebec

Adolescent mothers and low-birth-weight newborns in the Peruvian Amazon

Background: Adolescent pregnancy has been identified as the second most important problem in Iquitos, a city located in one of the poorest regions of Peru. Results from previous studies are mixed; however, young age has been suggested as a potential maternal risk factor of low birth weight (LBW).

Purpose: To explore LBW of infants born to adolescents (less than 20 years old).

Study Design: A random sample of 4 384 singleton live births from 2005 to 2007 was collected from a hospital birth registry in Iquitos, Peru.

Methods: Multiple logistic regression was performed to investigate whether a difference existed in LBW (< 2 500 g) between full-term live newborns of primiparous mothers less than 20 years old and primiparous mothers 20 years old and older. A further comparison was then made for early (10 to 14 years) versus late (15 to 19 years) adolescent mothers.

Results: A significant difference in LBW was found between 10 to 14 year olds and 20 year-olds-plus (odds ratio [OR] = 3.16, 95% confidence interval [CI]: 1.10 to 9.03). No significant difference was found between the other two age group comparisons.

Conclusions: These data suggest that early adolescence (10 to 14 years) is a risk factor for LBW in this population. These results provide much-needed critical evidence that will inform local health and education services to target suitable interventions to early adolescents.


A. Sarkar (1); H. Ouellette-Kuntz (1,2,3,4); H. Stuart (1,2,3)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Psychiatry, Queen’s University, Kingston, Ontario
  3. South Eastern Ontario Community-University Research Alliance in Intellectual Disabilities, Kingston, Ontario
  4. Ongwanada, Kingston, Ontario

An approach to studying the stigma experienced by parents of adults with developmental disabilities and dual diagnoses

Background: Stigma refers to a mark of social disgrace and can apply to any individual and/or groups seen as different in a negative sense. Those closely associated with stigmatized individuals (e.g. family) can also be affected by stigma (stigma-by-association). For individuals with a developmental disability or having both a developmental disability and a mental illness (dual diagnosis), social support often comes from parents who also feel stigmatized.

Purpose: 1) To assess the psychometric properties of two scales previously used to measure stigma-by-association in the field of mental illness when applied to our two groups of parents. 2) To describe the scope and magnitude of stigma reported by the parents. 3) To compare stigma experiences of our two groups of parents.

Methods: The proposed research will use a self-administered survey to measure the experience and impact of stigma in two groups of parents of adults with (a) developmental disabilities and (b) dual diagnoses. Each group will have 55 recruited participants. Reliability coefficient will be used to assess internal consistency, and data will be analyzed using descriptive statistics and comparing mean scale scores.

Results: Since the parents in both groups had adult children with intellectual disabilities, they were treated as one for the initial analysis of the two scales’ internal consistencies. For this study population, the scale that aimed to measure the degree of impact of stigma achieved excellent internal consistency (Cronbach’s alpha = 0.96) in our preliminary findings.


H. Scott (1); M. Chipman (2); W. Pickett (1); S. Bondy (1); P. Côté (1)

Author References

  1. Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario
  2. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario

Family matters: an examination of the association between family structure and youth non-sports injury risk

Background: This study represents a first attempt to examine the association between family structure (intact versus non-intact) and youth injury.

Purpose: To estimate the magnitude of and explore possible mechanisms that contribute to this association.

Study Design: This study was based on a representative, cross-sectional survey of 9 068 Canadian students, aged 11 to 15 years.

Methods: Poisson regression analyses were performed to examine the associations between family structure and youth injury outcomes and to assess hypothesized mediation by high-risk behaviours, after adjusting for potential confounders.

Results: Girls from non-intact families had only slightly increased risk of any type of injury compared with those from intact families (prevalence ratio [PR] = 1.11, 95% confidence interval [CI]: 1.04 to 1.19). However, they had a greater risk of any injury (PR = 1.30, 95% CI: 1.16 to 1.77) and severe injury (PR = 1.46, 95% CI: 1.12 to 1.91), respectively, occurring during unorganized activities. Secondly, this study illuminated differences in injury risk by gender: family structure was not associated with male injury risk.

Conclusions: These results give rise to two distinct directions for future research: 1) considering explanations that elucidate the components linking family structure to different types of injuries, and 2) examining the differences between male and female youth injury processes.


M. Shareck (1); M.-C. Rousseau (1,2); A. Koushik (1); J. Siemiatycki (1); M.-E. Parent (1,2)

Author References

  1. Université de Montréal, Montréal, Quebec
  2. INRS-Institut Armand-Frappier, Laval, Quebec

Dietary intake of antioxidants and risk of four histological subtypes of lung cancer: a population-based case-control study

Background: It is unclear whether the role of antioxidants in preventing lung cancer varies across tumour histological subtypes.

Objective: Data from a population-based case-control study conducted in Montréal (1996–1999) were used to assess the association between dietary intakes of β-carotene, α-carotene, β-cryptoxanthin, lutein/zeaxanthin, lycopene and vitamin C and risk of small cell carcinoma, squamous cell carcinoma, adenocarcinoma and large cell carcinoma.

Methods: In-person interviews elicited dietary data from 1 105 incident cases and 1 449 population controls. Using a food frequency questionnaire, we calculated the participants’ usual frequency of intake of 49 fruit and vegetables two years prior to diagnosis or interview and estimated antioxidant intakes from these. Adjusted odds ratios (OR) and 95% confidence intervals (CI) between intake variables and lung cancer histology were estimated using polytomous regression models.

Results: As compared to subjects in the lowest intake tertile, subjects in the highest tertile level of intake of each antioxidant had a lower risk of small cell carcinoma, squamous cell carcinoma and adenocarcinoma. For instance, statistically significant protective effects were found for high intakes of β-carotene (OR = 0.55, 95% CI: 0.4 to 0.8) and β-cryptoxanthin (OR = 0.49, 95% CI: 0.3 to 0.7) against squamous cell carcinoma.

Conclusion: Some antioxidants may protect against major lung cancer histological subtypes.


U. Shahzad (1,2); E. Talovikova (1,2); M. Alshurafa (1,2); and T. Haines(2, 3)  

Author References

  1. Bachelor of Health Sciences Honours Program, McMaster University, Hamilton, Ontario
  2. Department of Clinical Epidemiology and Statistics, McMaster University, Hamilton, Ontario
  3. Program in Occupational Health and Environmental Medicine (POHEM), McMaster University, Hamilton, Ontario

Documentation of occupational exposure history in medical charts of primary health care patients with asthma, hand or arm dermatitis, or carpal tunnel syndrome

Background: An important aspect of the diagnosis and management of asthma, hand and arm dermatitis (HAD), and carpal tunnel syndrome (CTS) is the occupational exposure history. However, occupational exposures are significantly under-reported in primary health care patient charts.

Purpose: To determine if occupational exposure was recorded in charts of primary care patients with asthma, HAD or CTS.

Study Design: Medical record review.

Methods: Using patient charts for the years 2000-2008 from three community health centres in Toronto, Ontario, data were abstracted about symptoms, diagnosis, and occupational exposures for randomly selected patients aged 24 to 65 years. Of these, 135 had asthma, 20 HAD and 39 CTS.

Results: Occupational exposure data were recorded in the medical charts of only 14% of asthma patients, 20% of HAD patients and 46% CTS patients. On average, practitioners established an occupational link in work-related asthma and CTS patients in 34 weeks and 14 weeks, respectively. Insufficient sample size prevented determination of this interval for dermatitis patients.

Conclusion: Occupational exposure was reported infrequently in charts of patients with asthma, HAD or CTS. Detection by physicians of adverse occupational exposures in their patients with asthma, HAD or CTS is a prerequisite to reducing exposure and preventing work-related deterioration.


C. Sirjoosingh (1); J. Gomes (2,3)

Author References

  1. Department of Epidemiology and Biostatistics, McGill University, Montréal, Quebec
  2. Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario
  3. McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario

Diabetes mellitus among Canada’s Aboriginal populations: an exploration of risk factors

Background: The prevalence of diabetes mellitus in Canada’s Aboriginal population has been increasing over the past few decades, with rates between two and five times higher than among non-Aboriginal populations.

Purpose: To identify known risk factors of type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) in the Canadian Aboriginal population.

Study Design: Systematic literature review

Methods: A systematic literature review of scientific literature from 1991 to 2006.

Results: From the review, 32 studies were found, along with 19 risk factors for T2DM and GDM. These studies were either prospectively designed analyses, or retrospective analyses of Aboriginal population-based surveys or databases. For Aboriginal people, genetic risk factors include HNF1A gene mutation G319S, family history and serum C-reactive protein levels. Other risk factors are age, sex, education level, obesity, waist-to-hip ratio, hypertriglyceridemic waist, smoking, physical activity, diet, birth weight and GDM. Specific risk factors for GDM are maternal age, blood pressure, multiparty and pregravid weight or body mass index (BMI).

Conclusions: Interventions targeted at the modifiable risk factors in an Aboriginal context may help lower rates of diabetes mellitus in this population.


B. T. Smith (1); J. W. Lynch (2); S. Harper (1); M. Abrahamowicz (1); C. S. Fox (3); E. B. Loucks (4)

Author References

  1. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec
  2. School of Health Sciences, University of South Australia, Adelaide, South Australia, Australia
  3. National Heart, Lung, and Blood Institute’s Framingham Heart Study, Framingham, Massachusetts, US
  4. Department of Community Health, Brown University, Providence, RI

Prospective study of life course socioeconomic position and incidence of type 2 diabetes mellitus: the experience of the Framingham Offspring Study

Background: Little is known about whether cumulative life course socioeconomic disadvantage influences the incidence of type 2 diabetes mellitus.

Purpose: To evaluate the associations between cumulative socioeconomic position (SEP) and type 2 diabetes mellitus incidence.

Study Design:Participants from the Framingham Offspring Study who were diabetes-free at baseline were followed from 1971 to 2003 (n = 1 895, 52% women, mean age 34 years).

Methods: Cumulative SEP score was calculated by summing scores for father’s education (< high school = 0, high school = 1, > high school = 2), own education (<= 12 years = 0, 13–16 years = 1, >= 17 years = 2) and own occupation (labourer = 0, clerical/sales/homemaker = 1, executive/professional/supervisory/technical = 2). Type 2 diabetes mellitus was defined as fasting plasma glucose >= 7.0 mmol/l or treatment with insulin or a hypoglycemic agent.

Results: Cox proportional hazards analyses demonstrated that age-adjusted cumulative SEP score was associated with type 2 diabetes mellitus risk in women (hazard ratio [HR] = 1.96, 95% confidence interval [CI]: 1.10 to 3.48 for low versus high cumulative SEP), but not in men (HR = 1.06, 95% CI: 0.70 to 1.61). Further adjustment for potential mediators, body mass index (BMI) (HR = 1.68, 95% CI: 0.94 to 3.00) and BMI, smoking, alcohol and height (HR = 1.47, 95% CI: 0.79 to 2.74) attenuated the association in women.

Conclusions: Cumulative SEP is inversely associated with type 2 diabetes mellitus risk in women, but not men; the strength of association appears to be accounted for in part through BMI.


C. A. Smith, J. Stokes, L. A. Newhook

Author References

  1. Faculty of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador

Clinical characteristics of type 1 diabetes mellitus diagnosed in children in Newfoundland and Labrador

Background: Type 1 diabetes mellitus (T1DM) is an insulin-dependent form of DM that usually develops in childhood or adolescence. Current epidemiological studies conducted on the clinical presentation of T1DM have shown considerable national/regional variability. The province of Newfoundland and Labrador (NL) has one of the highest incidences of T1DM in the world.

Purpose: To determine the clinical profile of patients with T1DM in the province of NL, specifically their presenting symptoms, laboratory measures, comorbidities, allergies and hospitalizations.

Study Design and Methods: Descriptive, bivariate and multivariate statistical analyses of data for prospective and retrospective cohort of children with T1DM treated in NL between 1980 and 2005.

Results: Data available for 631 children showed mean age at diagnosis of 9.3 years. Features at presentation included median serum glucose of 26.4 mmol/L. 62% with three or more symptoms, the most common being excess thirst (94%), polyuria (92%), and weight loss (48%). Bedwetting was reported in 20% of the children, ketoacidosis (DKA) in 24% and ketouria in 68%. Comorbid diseases were generally absent (65%), though asthma was the most common (10%). Allergies were reported in 28% of the participants, hospitalizations in 86% (multiple hospitalizations in 62%). Elevated serum glucose, allergies and DKA all significantly predicted for hospitalizations.

Conclusions: Clinical manifestation of NL children with T1DM is both heterogeneous and overall distinct from other studied jurisdictions.


M. Smith (1); M. Goldberg (2)

Author References

  1. McGill School of Environment, McGill University, Montréal, Quebec
  2. Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Quebec

Excess mortality due to tropospheric ozone: projections for Montréal using climate change scenarios

Background: Tropospheric (ground-level) ozone is associated with several adverse effects on human health, including increases in daily mortality. Formation of tropospheric ozone is largely temperature-dependent and future concentrations are predicted to increase due to global climate change.

Purpose: To predict future concentrations of tropospheric ozone in Montréal in 2030 so as to estimate excess mortality associated with the change.

Study Design: Time-series extrapolation.

Methods: A multiple regression model was used to predict concentrations of ozone in 2030 by extrapolating historical data from the period 1984 to 2003. Excess mortality was calculated using a pooled estimate of increased risk of mortality due to change in ozone concentrations, and, hence the attributable fraction and the number of deaths due to the projected change in ozone concentrations.

Results: Tropospheric ozone is projected to increase by 31% during the summer months of 2030 in Montréal. The estimated number of excess deaths associated with this increase is 100 (95% confidence interval [CI]: 61 to 138).

Conclusions: Although Montréal experiences relatively low air pollution compared to other cities, appreciable numbers of excess deaths are nonetheless projected to occur unless there are considerable reductions in greenhouse gas emissions.


M. Stegne (1); M. Tammemagi (1); G. Liu (2); H. Roberts (3)

Author References

  1. Community Health Sciences, Brock University, St. Catharines, Ontario
  2. Princess Margaret Hospital, Toronto, Ontario
  3. Toronto General Hospital, Toronto, Ontario

The associations between asbestos exposure, pulmonary function and computed tomography–found pulmonary fibrosis

Background: Occupational exposure to asbestos is known to increase the risk of developing both malignant and non-malignant diseases of the lung parenchyma and pleura, including pulmonary fibrosis.

Purpose: To determine the associations between asbestos exposure, pulmonary function indices, and computed tomography (CT)–found pulmonary fibrosis after controlling for potential confounders including smoking.

Study Design and Methods: Questionnaires were administered in a face-to-face interviews and low-dose CT scans was performed on 613 workers who were occupationally exposed to asbestos for an average of 24 years and had been recruited from the Occupational Health Clinics of Ontario Workers in Sarnia, Ontario, to participate in the Princess Margaret Hospital University Health Network “Early Diagnosis of Mesothelioma in Prior Asbestos Workers.” Medical records were abstracted to obtain all spirometric tests, and single-breath diffusing capacity (DLCO) tests were performed.

Results: Fibrosis of the lung parenchyma was found in 65 (10.66%) of the participants. Multivariate regression analysis showed that CT-found pulmonary fibrosis is associated with cumulative asbestos exposure (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.02 to 1.40) after controlling for smoking status. No significant interaction was found between asbestos exposure and smoking. No significant associations were found between pulmonary fibrosis and pulmonary function indices.

Conclusion: Asbestos exposure and smoking may play independent roles in pulmonary fibrosis development.


D. Sutton, W. Mackillop

Author References

  1. Division of Cancer Care and Epidemiology, Cancer Research Institute, Queen's University, Kingston, Ontario

Palliative radiotherapy utilization in Ontario

Background: Palliative radiotherapy (PRT) plays an important role in the management of end-stage cancer. However, little is known about the use of PRT on a population level.

Purpose: To describe the use of palliative radiotherapy in Ontario during the years 1983 to 2004.

Study Design: A population-based retrospective-cohort study.

Methods: The study population consisted of all cancer deaths in Ontario during the years 1983 to 2004. The proportion of patients receiving one course of PRT within the last two years of life (PRT rate) was described by various patient-related variables, such as age and sex, and health-system-related variables such as distance from a cancer center, and hospital of diagnosis.

Results: The overall rate of PRT for the entire study period was 25.2%. There were significantly higher rates of PRT utilization among men, among patients dying more than six months after diagnosis, among patients residing less than 50 km from the nearest cancer centre, and among patients diagnosed in a hospital affiliated with a Regional Cancer Centre. The overall rate of PRT fluctuated only slightly over time. However, the rate of PRT to the bone decreased from and 10.4% to 9.5% (p < 0.0001), while the rate of PRT to the brain increased from 2.2% to 5.1% (p < 0.0001).

Conclusions: The rate of PRT varied significantly according to the various patient and health system-related factors examined. A multivariate analysis will examine whether these factors are able to predict receipt of PRT.


C. Tassopoulos, H. Tamim

Author References

  1. School of Kinesiology and Health Science, York University, Toronto, Ontario

The role of health care providers and breastfeeding outcomes

Background: The role of health care providers has not been widely studied in relation to breastfeeding practices for Canadian women.

Purpose: 1) To assess the prevalence and characteristics of postpartum women who receive information and assistance by health care providers regarding breastfeeding, and 2) to determine the relationship between these offered services and breastfeeding outcomes.

Study Design: Secondary data analysis of the Maternity Experiences Survey (MES) developed by the Public Health Agency of Canada.

Methods: The MES sample consists of 6 421 mothers residing in Canada who had given birth to a singleton between February 15, 2006, and May 15, 2006. Breastfeeding outcomes will be defined as breastfeeding initiation and any breastfeeding until 6 months of age. Logistic regression will be used to assess characteristics of women offered breastfeeding services and to determine the relation between the role of health care providers and breastfeeding outcomes.

Results: Pending. This project is currently being submitted to the Research Data Centre for access to the microdata.

Conclusions: Pending. Results will enable the identification of the level of support needed from health care providers in order to augment breastfeeding practices.


M. Tazari (1,2); Y. Chen (1)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. School of Mathematics and Statistics, Carleton University, Ottawa, Ontario

Risk of heart disease in patients with rheumatoid arthritis

Background: Rheumatoid arthritis (RA) is one of most common forms of arthritis. RA is an inflammatory disease which mainly affects skeletal joints in the body but may also increase the risk of heart disease.

Purpose: To determine the risk of heart disease in rheumatoid arthritis patients and the risk factors that affect this association.

Methods: An analysis based on data from a national survey conducted in 2005, including 115 758 adult Canadians aged 18 years and older. A logistic regression model was used to adjust for covariates, and interaction between heart disease and covariates for effect modifier studied.

Results: The prevalence of heart disease increased in patients with rheumatoid arthritis (5.4%) in comparison to subjects without RA (4.8%). The risk of heart disease was higher in men than women. The prevalence ratio (PR) for men with RA (PR = 1.13; 95% confidence interval [CI]: 0.99 to 1.26) was higher than for women with RA (PR = 0.92, 95% CI: 0.78 to 1.05).

Conclusion: Rheumatoid arthritis is an important risk factor for heart disease.


M.-K. Tighe, R. Birtwhistle, P. Groome, H. Richardson

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario

Canadian family physician knowledge regarding breast cancer risk assessment

Background: It is important that family physicians (FP) know about breast cancer (BC) risk assessment and management to ensure that high-risk women are promptly identified and receive proper preventive care.

Purpose: To examine BC risk assessment and chemoprevention knowledge and practices among Canadian FPs.

Study Design: A cross-sectional nationwide mail survey.

Methods: We surveyed a random sample of 2 500 FPs selected from across Canada stratified by province. We used a modified Dillman approach, sending two mail-outs in both French and English over eight months. We conducted univariate analyses and multivariate logistic regressions using a stepwise selection procedure.

Results: While 97% of FPs correctly identified a woman with a family history of BC as being high risk, only 60% correctly identified a woman with a personal history of atypical benign breast disease as being high risk. Interestingly, 70% incorrectly believed hormone replacement therapy use placed a woman at high risk and 50% incorrectly believed being nulliparous over the age of 30 years also placed a woman at high risk for BC. Possible predictors of knowledge for each of these risk descriptions were examined.

Conclusions: FPs may need to become more aware about BC risk factors, and in particular those that place a woman at high risk for breast cancer development.


C. Tosevski, M. C. Tammemagi

Author References

  1. Department of Community Health Sciences, Brock University, St. Catharines, Ontario.

The relationship between body mass index and breast cancer recurrence and breast cancer–specific survival

Background: Elevated body mass index (BMI) is thought to be a risk factor for breast cancer. BMI influence on breast carcinogenesis may come into play after diagnosis.

Purpose: To examine the relationship between BMI and breast cancer recurrence/progression and breast cancer-specific survival.

Study Design: A historical cohort of 906 breast cancer patients diagnosed and treated at Henry Ford Health System between 1985 and 1990.

Methods: Logistic and Cox regressions assessed BMI and breast cancer recurrence/progression and breast cancer–specific survival. Restricted cubic splines evaluated BMI and outcomes in multivariable analysis. Probability of recurrence and progression and BMI was examined graphically.

Results: There were 236 recurrences/progressions and 181 breast cancer–specific deaths observed during the follow-up (median 10 years). Median BMI at diagnosis was 25.8. Nested models, including and excluding the four BMI spline variables, adjusted for stage (4 levels), treatment and number of adverse comorbidities, had a likelihood ratio test (LRT) of p =.001. Similar analysis with logistic regression for breast cancer recurrence/progression had an LRT of p = 0.16. Graphic evaluation of probability of recurrence/progression by BMI displayed a V-shaped pattern.

Conclusions: Our findings suggest a relationship between increasing risk of breast cancer-specific outcomes with BMI increasing or decreasing away from the mid-20s range.


J. Tota (1); C. M. Tammemagi (2)

Author References

  1. Division of Cancer Epidemiology, McGill University, Montréal, Quebec
  2. Department of Community Health Sciences, Brock University, St. Catharines, Ontario

Decision analysis of the effectiveness of lung cancer screening using autofluorescence bronchoscopy and computed tomography

Background: Lung cancer (LC) is the leading cause of cancer death in the developed world. A primary hope for reducing LC has been prevention of smoking and successful smoking cessation programs. To date, these programs have not been as successful as anticipated.

Objective: To evaluate whether LC screening combining low-dose computed tomography (CT) with autofluorescence bronchoscopy (AFB) is superior to CT or AFB screening alone in improving LC specific survival.

Methods: We applied decision analysis and Monte Carlo simulation modelling using TreeAge Software to evaluate our study aims. Histology- and stage-specific probabilities of lung cancer five-year survival proportions were taken from SEER Registry data. Screening-associated data were taken from the US NCI PLCO Cancer Screening Trial, National Lung Screening Trial, and US NCI Lung Screening Study, other published data and expert opinion.

Results: Decision Analysis – Combined CT and AFB was the best approach at improving 5-year survival (Overall Expected Survival (OES) in the entire screened population was 0.9863) and in lung cancer patients only (Lung Cancer Specific Expected Survival (LCSES) was 0.3256). Combined screening was slightly better than CT screening alone (OES = 0.9859; LCSES = 0.2966), and substantially better than AFB screening alone (OES = 0.9842; LCSES = 0.2124), which was considerably better than no screening (OES = 0.9829; LCSES = 0.1445). Monte Carlo simulation modeling revealed that expected survival in the screened population and lung cancer patients is highest when screened using CT and combined CT and AFB. CT alone and combined screening was substantially better than AFB screening alone or no screening. For LCSES, combined CT and AFB screening is significantly better than CT alone (0.3126 vs. 0.2938, p < 0.0001).

Conclusions: Overall, these analyses suggest that combined CT and AFB is slightly better than CT alone at improving lung cancer survival, and both approaches are substantially better than AFB screening alone or no screening.


A. R. Tuite (1,2); L. M. Kinlin (1,2); C. Kirchner (3); H. Zhang (3); D. N. Fisman (1,2,4)

Author References

  1. Research Institute of the Hospital for Sick Children, Toronto, Ontario
  2. University of Toronto, Toronto, Ontario
  3. Tenet Healthcare Corporation, Dallas, Texas, US
  4. Ontario Agency for Health Protection and Promotion, Toronto, Ontario

The impact of socioeconomic status on in-hospital mortality after acute myocardial infarction

Background: Associations between income and mortality after acute myocardial infarction (AMI) have been observed. Purpose: 1) To examine the relationship between income and in-hospital mortality following AMI, and 2) to identify factors mediating any observed association.

Study Design: Retrospective cohort.

Methods: From a database constructed by Tenet Healthcare, we extracted data on 38 473 patients admitted for AMI to 111 hospitals in the US. The relationship between neighbourhood-level income and mortality at discharge was examined with and without sequential risk adjustment for clinically-important covariates. In hospitals offering percutaneous transluminal coronary angioplasty (PTCA), we assessed the impact of income on treatment choice, a potential mediating factor.

Results: Income was inversely associated with mortality (crude odds ratio for high- versus low-income tertile, OR = 0.78, 95% confidence interval [CI]: 0.66 to 0.92). Adjustment for demographic characteristics, cardiovascular history, severity of AMI, comorbid conditions and in-hospital factors strengthened this effect (adjusted OR for high- versus low-income tertile, OR = 0.75, CI: 0.62 to 0.91). Income was also associated with increased use of PTCA compared to thrombolytics (adjusted OR for high- versus low-income tertile, OR = 2.20, CI: 1.22 to 3.99).

Conclusions: Income has a significant impact on in-hospital mortality after AMI. This relationship may be explained by systematic differences in therapeutic choice between income groups.


S. E. Vanderloo (1); J. A. Johnson (1,2); S. U. Balko (2); R. M. Couch (3); S. D. Marks (3); D. Pacaud (4); G. Hugel (2)

Author References

  1. School of Public Health, University of Alberta, Edmonton, Alberta
  2. Institute of Health Economics, Edmonton, Alberta
  3. Faculty of Medicine, University of Alberta, Alberta
  4. Faculty of Medicine, University of Calgary, Alberta

Incidence of diabetes mellitus among Albertans under the age of twenty years between 1995 and 2007

Background: Incidence of diabetes mellitus is increasing globally, with rates of type 1 and 2 diabetes mellitus increasing among children and adolescents.

Purpose: To examine trends in the incidence of diabetes among people under 20 years old in Alberta, Canada.

Study Design: Descriptive study design.

Methods: Data for Albertans under 20 years old were collected from the Alberta Health and Wellness administrative databases using the National Diabetes Surveillance System case definition: one hospitalization discharged with a diagnosis with an ICD-9 or ICD-10 code for diabetes or two medical claims with an ICD-9 code of 250 within 2 years. These data do not differentiate between type 1 and type 2 diabetes mellitus. Age-specific incidence rates were compared over a period of twelve years (1995–2007) using logistic regression.

Results: Overall, incidence rates increased between the years 1995 and 2007; rates plateaued or declining between 2002 and 2006.

Conclusions: The overall incidence of diabetes among Albertans less than 20 years old has increased over the past twelve years in Alberta. Declining rates observed in the years 2002 to 2006 may have resulted from the introduction of the ICD10-CA coding in 2002 and/or the Alternate Relationship Plan adopted by pediatric endocrinologists in the province in 2003. These speculations require further investigation.


M. P. Vélez (1); B. E. Alvarado (2); M. V. Zunzunegui (1)

Author References

  1. Département de médecine sociale et préventive, Université de Montréal, Montréal, Quebec
  2. Department of Epidemiology and Biostatistics, McGill University, Montréal, Quebec

Life-course social adversity and age at menopause in women from Latin America and the Caribbean

Background: Earlier age at menopause has been related to poor life-course social conditions in high income countries. This association has not been examined in lower income countries.

Purpose: To assess the association between life-course social adversity and age at menopause in Latin America and the Caribbean (LAC).

Methods: Data from 3 783 women aged 60 to 79 years randomly selected from seven cities in LAC were analyzed. Multiple linear regressions were used to estimate the difference in age at menopause associated with social adversity.

Results: Age-adjusted mean age at menopause was 46.6 years (standard error [SE] = 1.08). Women with the following life-course social adversities began menopause earlier: low socioeconomic status during childhood (0.45 years earlier; 95% confidence interval [CI]: 0.04 to 0.86); poor health during childhood (0.44 years earlier; 95% CI: 0.06 to 0.82); low education (1.31 years earlier; 95% CI: 0.89 to 1.75); and housewives and lifelong manual work (0.97 years earlier; 95% CI: 0.57 to 1.37). All associations remained significant in the fully adjusted model which included nulliparity, smoking, knee-height and all others life-course social adversity indicators.

Conclusions: Age at menopause in women from LAC occurs several years earlier compared to women from high income countries (about 53 to 54 years). Results support the association of life-course social adversity and age at menopause.


S. C. Wallingford (1); G. Jones (2); K. J. Aronson (1)

Author References

  1. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  2. Department of Biochemistry, Queen’s University, Kingston, Ontario

Vitamin D status in winter and summer among nurses

Background: Recent research indicates that inadequate vitamin D status may incur increased cancer risk. Vitamin D is made in the skin through direct absorption of sunlight; however, during winter at latitudes above 40° N, UVB rays are insufficient to permit this synthesis. Vitamin D can also be obtained from natural and fortified dietary sources and supplements.

Purpose: To describe seasonal variations in vitamin D status in nurses and to investigate lifestyle and dietary determinants of this status.

Study Design: Cross-sectional study.

Methods: Forty-four healthy, pre-menopausal nurses from Kingston General Hospital volunteered to complete a questionnaire and provide two blood samples, one in May–July 2008 to represent winter status, and one in October–December 2008, to represent summer status. Vitamin D status, as measured through serum 25-hydroxyvitamin D [25(OH)D], was quantified by radioimmunoassay.

Results: Mean serum 25(OH)D concentrations were 32 ng/mL and 42 ng/mL for winter and summer, respectively. The prevalence of vitamin D insufficiency in winter was 51% compared to 26% in summer (p = 0.02). Within individuals, a significant difference in 25(OH)D levels between seasons was observed (p = 0.0003). Tanning bed and supplement use were significant determinants of serum 25(OH)D concentrations.

Conclusion: Vitamin D insufficiency is prevalent in this population.

G. Warden, T. Wish, P. S. Parfrey

Author References

  1. Department of Medicine, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador

Familial microsatellite stable colorectal cancer in a cohort of seniors

Background: Colorectal cancer (CRC) has a strong familial component with a small proportion of incident CRC attributable to mutations in known mismatch repair genes. A familial microsatellite-stable colorectal cancer (MSS FCC-X) was recently clinically characterized. In Newfoundland, a substantial proportion of CRC occurs in individuals with MSS CRC and a family history consistent with an autosomal dominant disease. A cohort of CRC patients 75 years and older were identified with family histories, and the cancer pathology was examined to determine the proportion which may have this monogenic disease.

Purpose: 1) To classify the cohort by mismatch repair gene mutations and family history criteria suggestive of MSS FCC-X; 2) to evaluate the cancer risk in family members stratified by molecular genetic markers and family history.

Study Design: Retrospective cohort study

Methods: The Newfoundland Colorectal Cancer registry confirmed the pathology of 300 CRC patients over 75 years of age. After identification of microsatellite instability (MSI), familial risk, type, age of cancer/polyps, microsatellite stability and immunochemistry results, we will determine the genotype/phenotype relationship if novel genes are identified in the lab.

Results: Pending.

Conclusions: Pending.


J. Warsh (1); I. Janssen (1,2); W. Pickett (1)

Author References

  1. Department of Community Health and Epidemiology, Queen's University, Kingston, Ontario
  2. School of Kinesiology and Health Studies, Queen’s University, Kingston, Ontario

Do overweight and obese youth take longer to recover from fractures, sprains and strains?

Background: Injury and obesity are common health issues in youth. Obese youths demonstrate greater complications and longer recovery time following injury that can lead to changes in regular activity or school attendance, which can, in turn, have a major impact on their lives.

Objective: To examine the effect of adiposity status on the time to recovery among Canadian youth who have suffered one or more sentinel types of injury.

Methods: Data were obtained from the 2002 Canadian Health Behaviour in School-aged Children (HBSC) survey, a nationally representative survey of 7 266 youth from all provinces and territories. Kaplan-Meier curves and hazard ratios (HR) were used to profile survival functions and estimate relative hazards for non-recovery among normal, overweight and obese youth.

Results: Youth who were obese and suffered a major injury (broken bone and strain/sprain) took longer to recover (HR = 1.81, 95% confidence interval [CI]: 0.99 to 3.32). Hazard ratios for obese youth also showed consistent, non-significant increases in injury recovery length as compared to normal weight youth for broken bones (HR = 1.15, 95% CI: 0.61 to 2.19) and sprain/strains (HR = 1.17, 95% CI: 0.73 to 1.85).

Conclusions: Adiposity influences injury recovery time, especially for major injuries


M. Weir (1,2); J. Grimshaw (2,3); D. Fergusson (1,4); A. Mayhew (3)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Faculty of Medicine, University of Ottawa, Ottawa, Ontario
  3. Cochrane Effective Practice and Organisation of Care (EPOC) Group, Institute of Population Health, University of Ottawa, Ottawa, Ontario
  4. Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario

Meta-epidemiology: an overview of systematic reviews

Background: With the increasing number of journal articles being published each year, systematic reviews (SRs) are being increasingly used as a way to obtain an objective summary of a large amount of evidence. There has been an increase in the number of SRs published over the years on professional behaviour change interventions; however, the quality of these reviews varies, depending on the extent to which scientific review methods were used in their development to minimize error and bias, and multiple reviews are often published on the same clinical question which results in a redundancy of literature and duplication of efforts by reviewers.

Purpose: To determine the epidemiology and assess the quality and methods of SRs of professional behaviour change interventions.

Study Design and Methods: A broad description of the field of professional behaviour change interventions was conducted and a quality assessment of SRs was conducted using AMSTAR, a measurement tool to assess the methodological quality of SRs.

Results: Pending.

Conclusions: The results will suggest the optimal organization and methodology of SRs of professional behaviour change interventions and will challenge authors of professional behaviour change reviews to address the quality and methods of their SRs.


C. M. White (1); M. R. Cheverie (1); S. L. Tyas (1,2)

Author References

  1. Department of Health Studies and Gerontology, University of Waterloo, Waterloo, Ontario, Canada
  2. Department of Psychology, University of Waterloo, Waterloo, Ontario, Canada

Education and healthy aging: the role of income and occupation

Background: Although many studies have found an association between education and healthy aging, the mechanisms for this association remain unclear.

Purpose: To investigate the roles of income and occupation as potential mediators of the association between education and healthy aging.

Study Design: Analyses of data from 1 751 community-dwelling individuals aged 65 years plus in the Manitoba Study of Health and Aging, a longitudinal, population-based study conducted in parallel with the Canadian Study of Health and Aging.

Methods: The healthy aging construct was composed of cognitive, physical, social and psychological health measures. Occupation was classified according to Statistics Canada Standard Occupational Classifications. Logistic regression modelling was used to explore the relationship between education at baseline and healthy aging five years later and to investigate income and occupation as mediators of this relationship.

Results: Increasing educational attainment was a significant predictor of healthy aging (OR = 1.16; 95% CI = 1.08-1.25). The association between education and healthy aging was not significantly reduced when income satisfaction was considered (OR = 1.15; 95% CI= 1.07-1.24).

Conclusions: Income satisfaction did not have a mediating effect on the relationship between education and healthy aging. Exploration of alternate mechanisms through which education may be associated with healthy aging, such as occupation, could help maximize the likelihood of healthy aging for all.


S. White (1); A. M. Whelan (2); G. Flowerdew (1); M. Asbridge (1); D. Langille (1)

Author References

  1. Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia
  2. College of Pharmacy, Dalhousie University, Halifax, Nova Scotia

Knowledge of emergency contraception among women in Nova Scotia, Canada

Background: In 2005, the Canadian government made Plan B®, a type of emergency contraception (EC), available without a prescription. Recent qualitative evidence indicates that despite this policy change, Nova Scotian women may know little about EC.

Purpose: We investigated whether women’s knowledge of EC differs by age, education level, income, relationship status and religiosity.

Study Design: Cross-sectional survey.

Methods: A random-digit dial telephone survey was administered to 717 Nova Scotian women aged 18 to 51 years. Data were analyzed using univariate and linear regression approaches.

Results: 30.1% of respondents (216) of respondents knew that Plan B® was available without a prescription. Knowledge scores differed between 18 to 32 year old women and 33 to 51 year old women (p < .0001). A higher proportion of younger women answered five out of the seven questions correctly (p < .001). Higher levels of education were associated with increased knowledge scores (p < .01). Those in a non-cohabiting relationship had the highest knowledge scores, whereas married women and those with strong religiosity had lower scores (p < .001).

Conclusions: Many Nova Scotian women are unaware of the availability of Plan B® at pharmacies without prescription. Education level, religiosity and relationship status were associated with EC knowledge


R. Wilson (1); J. McDonald (2); B. Barrett (1); P. Parfrey (1)

Author References

  1. Clinical Epidemiology Unit, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador
  2. Patient Research Centre, Eastern Health, St. John’s, Newfoundland and Labrador

On planning the restructuring of institutional long-term care in Newfoundland, Canada: validity of assumptions regarding bed use

Background: There is a mismatch between the needs of long-term care (LTC) patients and bed use in Newfoundland. To plan the restructuring of institutional LTC in the St. John’s region, an incident cohort through the single entry system was studied in 1995/96 and in 1999/2000.

Purpose: To test the stability of these assumptions and to review bed need, using another incident cohort requesting institutional LTC in 2005/06.

Study Design: Cohort Study.

Methods: Bed need was predicted using a decision tree and assumptions made on demographic change, incidence rates, degree of disability, adherence to guidelines, community care availability and survival.

Results: From 1995-2006, the rate of supervised care and nursing home beds per 1 000 of the population aged 75 years and older increased by 20%; however, incidence rate of clients for LTC increased by 36%. The match between need and placement recommendation improved, but appropriate housing facilities for those with no disability and specialized supervised care for those with cognitive impairment were not available. The stability of estimates for demographic change and survival is pending.

Conclusions: Some important assumptions made to predict bed need are not stable and require constant review.


J. Wong, Y. Chen

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario

Can regular visits to the dentist reduce the risk of heart disease?

Background: Visiting a dentist regularly is one way of preventing periodontal diseases and promoting good oral health. Studies have shown a positive association between periodontal and cardiovascular diseases.

Purpose: To investigate the association between the frequency of regular dental visits and heart disease status.

Study Design: Analysis of cross-sectional data from the 2005 Canadian Community Health Survey. The study population includes respondents aged 20 to 75 years from Ontario and Saskatchewan who completed a survey module on oral health.

Methods: Multivariate logistic regression modelling to calculate the odds of heart disease associated with visiting the dentist at least less than once per year compared to visiting the dentist for emergency care only or never.

Results: The adjusted odds ratio (plus 99% CI) associated with visiting the dentist at least less than once per year was 0.91 (0.75-1.10) in males and 0.72 (0.59-0.88) in females, thus suggesting that visiting the dentist on a regular basis may be associated with decreased risk of heart disease, especially among women.

Conclusions: Visiting the dentist regularly may be associated with a reduced risk of heart disease. If this association remains upon further analysis, this suggests that efforts to increase access to professional dental care may help reduce the burden of heart disease in the population.


J. Wong (1); S. Y. Pan (2); J. Gomes (3)

Author References

  1. Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario
  2. Centre for Chronic Disease Prevention and Control, Public Health Agency of Canada, Ottawa, Ontario
  3. Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario

A case-control study of dietary factors and the risk of brain cancer in Canada

Background: Epidemiological evidence on the association between diet and brain cancer is limited and inconsistent. The predominant hypothesis is that foods containing N-nitroso compounds may increase brain cancer risk.

Purpose: To investigate the association between risk of adult brain cancer and intake of certain nutrients previously found or hypothesized to be associated with the development of brain cancer.

Study Design: (1) Literature review identifying all previous epidemiological studies investigating the association between diet and brain cancer risk. (2) A population-based case-control study using data from the Canadian National Enhanced Cancer Surveillance System to investigate the association between reported dietary intakes of selected nutrients and the risk of brain cancer.

Methods: Logistic regression methods to obtain adjusted odds ratios and 95% confidence intervals for the association between brain cancer and different levels of intake of dietary nutrients.

Results: No associations were observed for consumption of dietary sources of N-nitroso compounds or higher intake of fruits and vegetables. Increased risks were observed for higher intakes of total energy, fat, cereal and coffee. Decreased risks were observed for higher intakes of fish, bread, grains and use of some mineral supplements.

Conclusions: This study does not support the hypothesis that dietary intake of N-nitroso compounds increases brain cancer risk.


J. Wu (1,2); S. Gill (3,4); L. Lévesque (4,5)

Author References

  1. Faculty of Health Sciences, Queen’s University, Kingston, Ontario
  2. School of Public Health, Yale University, New Haven, Connecticut, US
  3. Department of Medicine, Queen’s University, Kingston, Ontario
  4. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario
  5. Kingston, Frontenac, and Lennox & Addington Public Health, Kingston, Ontario

Representativity of patients with atrial fibrillation in antithrombotic trials

Background: The representativity of antithrombotics trial participants is unknown.

Purpose: To compare the clinical profiles of antithrombotics trial participants and older adults treated in routine practice, and determine the proportion of the general practice population eligible for enrolment in such trials.

Study Design: Systematic review of randomized controlled trials and retrospective cohort study.

Methods: Using the administrative health databases of Quebec, we conducted a systematic review to identify antithrombotic trials and formed a cohort of older adults (>= 65 years) treated with an antithrombotic from 1995 to 2006. The weighted means and frequencies of the characteristics of the trial population were compared with those of the cohort using t-tests and chi-square tests respectively. We also calculated the proportion of cohort members meeting at least one exclusion criteria. Results: A total of 15 900 individuals were pooled across 16 included trials and 14 131 formed the cohort population. Overall, cohort members were significantly older, more likely to be female and to have multiple comorbidities, but took fewer medications than trial participants. In addition, only 10% to 30% of cohort members would have been eligible for trial enrolment.

Conclusion: The clinical trial population that established the benefit-risk ratio of antithrombotics does not appear to represent individuals treated in routine practice.


B. Yama (1,8); G. Y. Zou (1,2); T. Freeman (3); D. MacFabe (4,5,6); M. K. Campbell (1,7,8)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Robarts Clinical Trials, Robarts Research Institute, London, Ontario
  3. Department of Family Medicine, University of Western Ontario, London, Ontario
  4. Kilee Patchell-Evans Autism Research Group, University of Western Ontario, London, Ontario
  5. Department of Psychology, University of Western Ontario, London, Ontario
  6. Department of Psychiatry, University of Western Ontario, London, Ontario
  7. Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario
  8. Children’s Health Research Institute, London, Ontario

Screening for autism in a prenatally assembled cohort

Background: The M-CHAT is a 23-question screening test that facilitates the early detection of autism in toddlers.

Purpose: (1) To identify health service utilization and child/family health indicators predictive of M-CHAT performance. (2) To identify clinically relevant indicator(s) of M-CHAT performance that clinicians could apply to identify a subgroup that should be screened for autism.

Study Design and Methods: Data were obtained from a population based prospective cohort study (n = 1 570). Univariable analyses were used to select variables to be used in prediction. Predictive variables with p-values less or equal to 0.25 were included in a forward stepwise binary logistic regression model and a recursive partitioning model.

Results and Conclusions: Sixty-five children (4.14%) failed the M-CHAT. Children whose parents express concern about their development had higher chance of failing the M-CHAT (odds ratio [OR] = 3.58, 95% confidence interval [CI]: 1.688 to 6.794). Recursive partitioning shows that by restricting screening to children whose mothers express concern about their child’s development, the sample could be decreased to n = 118 with a failure rate of 12.7% (n = 15). Thus, 23% of failures could be detected by screening 8% of the sample. These findings have policy implications for screening opportunities promoting the early detection of autism.


J. Yang (1); M. Wang (2); A. Belch (3)

Author References

  1. Department of Public Health Sciences, University of Alberta, Edmonton, Alberta
  2. Surveillance Analytic Team, Alberta Cancer Board, Edmonton, Alberta
  3. Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta

Patterns of survival in multiple myeloma: a population-based study of patients diagnosed in Alberta, Canada, from 1976 to 2006

Background: Multiple myeloma is the second most prevalent blood cancer after non-Hodgkin's lymphoma in Canada. It represents approximately 1% of all cancers and 2% of all cancer deaths.

Purpose: To define variations in the patterns of survival in a large population-based, multiple-centred and retrospective cohort.

Study Design: Retrospective cohort study.

Methods: We used the SAS and the period analysis method to compare the one-year, three-year and five-year relative survival ratios (RSRs).

Results/Conclusions: When the calendar period was stratified, the 1-year RSRs increased from 69.7 in 1976-1985 to 72.7 in 2004-2006. The 3-year RSRs increased from 39.9 in 1976-1985 to 48.8 in 2004-2006. The 5-year RSRs increased from 21.8 in 1976-1985 to 31.8 in 2004-2006. When the calendar period and age category were stratified, the multiple myeloma RSRs increased in patients 70 years old or younger from 1996-2000 to 2004-2006; the 3-year RSRs in 0-60 years old were 48.16 in 1996-2000 and 65.9 in 2004-2006; 61-70 years old RSRs were 45.6 in 1996-2000 to 55.8 in 2004-2006. The 5-year RSRs in 0-60 years old were 38.41 in 1996-2000 to 53.5 in 2004-2006; 61-70 years old RSRs were 32.66 1996-2000 to 35.7 in 2004-2006. But a significant increase can be found in patients older than 70 years.


S. Yuan (1); A. Thind (1,2); B. Xie (1,3); M. K. Campbell (1,4)

Author References

  1. Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario
  2. Department of Family Medicine, University of Western Ontario, London, Ontario
  3. Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario
  4. Children’s Health Research Institute, London, Ontario

Maternal marital status and children’s health services use

Background: Women’s marital status is associated with health status, employment and income. In mothers, these traits affect children’s health services use (HSU).

Purpose: To examine the influence of maternal marital status on children’s HSU as a first step to determining whether children’s HSU is equitable and driven by health needs rather than factors such as parental income.

Study Design: A cohort of 1 596 women and their children (ages 2 to 5) from the Prenatal Health Project (PHP) was examined. The PHP is a longitudinal study of 2 357 women recruited during pregnancy in 2003 from the London-Middlesex region.

Methods: A conceptual model based on the Andersen Behavioural Model was used. First, unmet needs and barriers to HSU were described. Participants’ reasons for not seeking care when their child experienced health symptoms were explored, as were the types of services that could not be accessed due to barriers. Second, a nested multinomial model was used to determine how marital status and other factors influence children’s use of primary care, walk-in clinics and the emergency department.

Results: Pending.

Conclusions: The study results have important policy implications as they will help elucidate the determinants of children’s HSU within the Canadian context and identify factors that may prevent, or enable, HSU.


L. Zhao (1); R. N. Lajeunesse (1); C. Lajeunesse (1), J. Gomes (1,2)

Author References

  1. Faculty of Health Sciences, University of Ottawa, Ontario
  2. R. Samuel McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario

Endocrine-disrupting chemicals and prostate cancer: a review and meta-analysis

Background: Prostate cancer is the most commonly diagnosed cancer among men in Canada. Although its specific causes remain unknown, a relationship between hormones and prostate cancer has been described. Some environmental and industrial compounds can mimic, alter or block endogenous hormone action and these compounds are classified as endocrine disrupting chemicals (EDCs).

Purpose: To review and synthesize available epidemiological evidence on the relationship between exposure to EDCs and prostate cancer.

Methods: We conducted a systematic search of literature using various Internet-based databases (CINAHL, EMBASE, Ovid, PubMed, Scopus and Toxline). Studies meeting the inclusion and exclusion criteria were retained for review. Meta-analyses were performed on the prostate cancer risk estimates for exposures to overall EDCs and to EDCs broadly grouped by endocrine activity status (established, potential, probable), agent group (biocidal products, organohalogens, others) and hormone system affected (androgen, estrogen, thyroid).

Results: We found evidence of association of prostate cancer and exposures to EDCs. The meta-analyses found significant positive associations between the various EDC groups and prostate cancer, except for EDCs affecting the androgen hormone system.

Conclusion: Substantial further research is necessary to study the relationship between individual EDCs and more specific EDC groupings and prostate cancer.

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