Chronic disease and chronic disease risk factors among First Nations, Inuit and Métis populations of northern Canada
S. G. Bruce, PhD; N. D. Riediger, MSc; L. M. Lix, PhD
This article has been peer reviewed.
Department of Community Health Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
Correspondence: Sharon Bruce, Associate Professor, Department of Community Health Sciences, College of Medicine, Faculty of Health Sciences, University of Manitoba, S113-750 Bannatyne Avenue, Winnipeg, MB R3E 0W3; Tel.: 204-975-7745; Fax: 204-789-3905; Email: email@example.com
Introduction: Aboriginal populations in northern Canada are experiencing rapid changes in their environments, which may negatively impact on health status. The purpose of our study was to compare chronic conditions and risk factors in northern Aboriginal populations, including First Nations (FN), Inuit and Métis populations, and northern non-Aboriginal populations.
Methods: Data were from the Canadian Community Health Survey for the period from 2005 to 2008. Weighted multiple logistic regression models tested the association between ethnic groups and health outcomes. Model covariates were age, sex, territory of residence, education and income. Odds ratios (ORs) are reported and a bootstrap method calculated 95% confidence intervals (CIs) and p values.
Results: Odds of having at least one chronic condition was significantly lower for the Inuit (OR = 0.59; 95% CI: 0.43–0.81) than for non-Aboriginal population, but similar among FN, Métis and non-Aboriginal populations. Prevalence of many risk factors was significantly different for Inuit, FN and Métis populations.
Conclusion: Aboriginal populations in Canada's north have heterogeneous health status. Continued chronic disease and risk factor surveillance will be important to monitor changes over time and to evaluate the impact of public health interventions.
Keywords: Aboriginal, First Nations, Inuit, Métis, chronic disease, northern Canada
Aboriginal populations in Canada's north comprise three distinct groups, First Nations (FN), Inuit and Métis, each with their own histories, lifeways and relationships with the Government of Canada. Canada's northern territories, the Yukon, Northwest Territories (NWT) and Nunavut, have the largest proportion of Aboriginal people of any region in Canada. Overall, 40% of northern Canadians living in the territories are Aboriginal, compared to only 4% of the total Canadian population.Endnote 1 In Nunavut, 85% of the population is Aboriginal, over 90% of whom are Inuit. In the NWT, 50% of the population is Aboriginal (FN, 61%; Inuit, 20%; Métis, 17%) and in the Yukon, 25% of the population is Aboriginal (FN, 83%; Métis, 11%; Inuit, 4%).Endnote *
In the past half century, the Aboriginal populations of northern Canada have undergone a significant health transition characterized by a decline in infectious diseases and an increase in chronic conditions such as diabetes, obesity, heart disease and respiratory illnesses. This is paralleled by an increase in social problems such as violence, accidents and substance abuse.Endnote 2 These phenomena are strongly interrelated through the effects of colonization and the subsequent changes in both physical and social environments.Endnote 3
The epidemiological transition is proceeding at a different pace for Aboriginal peoples in southern and northern Canada. As Lix et al.Endnote 4 described, the burden of chronic diseases and risk factors for chronic diseases is high in the south and emerging in the north. Chronic disease and risk factor surveillance is important among populations undergoing rapid changes in health and can help in developing interventions. It is important for FN, Inuit and Métis governing bodies to understand and act upon issues that affect their people specifically because each of these Aboriginal groups represent distinct groups with unique relationships to the federal, provincial and local governments. Therefore, Aboriginal groups require data that are relevant to their own people, regardless of jurisdiction.
To date there has been scant research comparing chronic disease and risk and protective factor prevalence in the three Aboriginal populations in northern Canada. The purpose of our research was:
- to describe and compare the prevalence of chronic conditions and risk factors among the FN, Inuit, and Métis populations and
- to compare these populations to northern non-Aboriginal populations.
We used data from cycles 3.1 (2005/2006) and 4.1 (2007/2008) of the Canadian Community Health Survey (CCHS) for this research. The CCHS is a national survey conducted by Statistics Canada that contains questions about health care status, determinants of health and health system use for 136 health regions in Canada. The CCHS covers approximately 98% of the entire Canadian population aged 12 years or older. People living on Indian reserves and other government-owned land and in institutions as well as full-time members of the Canadian Forces are excluded from the survey. In Yukon and Nunavut, Aboriginal people do not live on reserve, nor do over 99% of the people in NWT.Endnote 5 In Nunavut, the CCHS only collects information from the 10 largest communities; therefore 71% of the population of this territory is covered by the survey.Endnote 6 Data from the two CCHS cycles were combined to allow adequate sample size to investigate multiple chronic diseases and risk factors.
Sample sizes for cycles 3.1 and 4.1 of the CCHS were 132 947 and 131 959, respectively. Response rates for cycle 3.1 were 78.9% for the total Canadian sample, 81.6% for Yukon, 81.7% for NWT and 87.7% for Nunavut. In cycle 4.1, response rates were 76.4% for total Canadian sample, 83.0% for Yukon, 85.0% for NWT and 85.4% for Nunavut. Included in this study are all respondents to cycle 3.1 or cycle 4.1 aged 20 years and older who reported Yukon, NWT or Nunavut as their region of residence. Therefore, the non-Aboriginal comparison population is also northern.
Our research was approved by the University of Manitoba Health Research Ethics Board. Statistics Canada approved access to the data; analyses were conducted within the secure environment of the Statistics Canada Research Data Centre located at the University of Manitoba.
In each cycle of the CCHS, respondents were asked if they self-identified with one of the three constitutionally recognized Aboriginal groups. Those who identified with more than one ethnic group were assigned to the FN group. Given the small sample size, we did not want to exclude any individuals. Respondents who selected an ethnic group other than the three Aboriginal groups were defined as non-Aboriginal. Therefore, the ethnic categories for this study are FN, Inuit, Métis and non-Aboriginal.
In addition to age and sex, respondents were characterized by total household income and highest level of education. Education was categorized as less than secondary, secondary and post-secondary. Respondents were asked to provide an estimate of total household income from all sources, before taxes and deductions, in the past 12 months; total household income was assigned to one of four categories: $0 to $29 999, $30 000 to $59 999, $60 000 to $99 999, and $100 000 or more.
Respondents were asked about long-term chronic health conditions that were expected to last, or had already lasted 6 months or more and been diagnosed by a health care professional. Multiple chronic conditions are included in this analysis: arthritis/rheumatism, asthma, bowel disorders, cancer, diabetes, emphysema/ chronic obstructive pulmonary disease (COPD), heart disease, high blood pressure and stroke. Dichotomous variables (i.e. presence/absence) were created for each condition. In addition, a single variable was created for an individual's overall level of morbidity. Specifically, the presence of at least one of the following chronic conditions was used to create a binary morbidity variable: arthritis/rheumatism, asthma, high blood pressure, diabetes, heart disease, cancer, stroke, chronic bronchitis, emphysema, COPD, bowel disorders, anxiety disorder, mood disorder, migraine headaches, dementia, stomach or intestinal ulcers, urinary incontinence and back problems.
We also investigated a number of risk and protective factors including alcohol consumption, cigarette smoking, body mass index (BMI) and leisure-time and regular physical activity. Risk factors included as part of the optional module in the CCHS were excluded. We categorized alcohol consumption as follows: non-drinker; occasional (< 1 drink/month in the past 12 months); regular (≥ 1 drink/month in the past 12 months); and heavy (≥ 5 drinks on at least one occasion in the past 12 months).Endnote 7 Possible responses on the frequency of cigarette smoking were daily, occasionally or non-smoker. Dichotomous variables (yes/no) were created for each category; for example, odds ratio for daily smoking are reported as compared to nonsmokers. Variables were dichotomized to improve interpretation and also minimize the effect of small cell sizes as we crosstabulated with the explanatory variables. We determined the chronic conditions and risk factors to select based on availability in the dataset as well as theoretical considerations; many of the chronic conditions have already been implicated in the epidemiological transition that is emerging in the north.Endnote 4, Endnote 8 All of the risk factors were related to multiple chronic conditions, are inter-related and/or are markers of broader community and structural factors. For example, alcohol use is associated with heart disease, blood pressure, anxiety disorders, mood disorders and bowel disorders.Endnote 9, Endnote 10, Endnote 11 Smoking is associated with asthma, chronic bronchitis, diabetes, heart disease and high blood pressure.Endnote 12 Overweight and obesity are associated with arthritis, asthma, diabetes, heart disease, high blood pressure, bowel disorders, anxiety disorders and mood disorders.Endnote 13, Endnote 14
BMI was calculated from self-reported height and weight data.Endnote 15 Overweight was defined as BMI of 25.00 to 29.99 kg/m2 and obesity as BMI of 30.0 kg/m2 or higher.Endnote 16
Respondents were asked to report the frequency of all physical activities not related to work lasting over 15 minutes for the 3-month period before the date of the interview. Average monthly frequency was then calculated. Physical activity level was categorized as follows: regular (≥ 12 occasions/month); occasional (4–11 occasions/ month); and infrequent (< 4 occasions/ month). Dichotomous variables (yes/ no) were formed for each category of physical activity. Levels of leisure-time physical activity were derived based on each respondent's total daily energy expenditure during leisure-time physical activities Endnote 17 and was defined as active (≥3.0 kcal/ kg/day), moderate (1.5–2.99 kcal/kg/day) or inactive (0–1.49 kcal/kg/day). Leisuretime physical activities included walking, running, cycling, swimming, home exercise, exercise classes, fishing and gardening and also playing team sports such as ice hockey, basketball, volleyball and soccer. Each category of leisure-time physical activities was dichotomized (yes/no).
Finally, we investigated an overall measure of health. Respondents were asked to rate their own health with 5 options ranging from excellent to poor. Subsequently, we combined the 5 categories of self-rated health into 2: excellent, very good and good in one, and fair and poor in the other. (For further information on self-rated health in indigenous populations, see Bombak and Bruce SG.Endnote 18)
Data from the two cycles were combined using a pooled estimate method.Endnote 19 Descriptive analyses of the total number of respondents and their sociodemographic characteristics were conducted in an unweighted analysis. Crude prevalence of the selected chronic diseases, risk factors and self-rated health were calculated with 95% confidence intervals (CIs) using the sampling weights, which ensures that the estimates are representative of the study population.
Weighted multiple logistic regression analyses were used to test the association between ethnicity and each of the measures of chronic disease, health risk and self-rated health. In addition to ethnic group, the covariates included age group (20–34 years, 35–54 years, 55+ years), sex, territory of residence, education level and total household income. The reference categories were the 55+ years age group, male sex, non-Aboriginal ethnicity for analyses that included all ethnic groups and FN for within-Aboriginal group analyses, NWT residence, less than secondary education and lowest income category ($0–$29 999).
We used a bootstrap method to calculate 95% CIs for the crude prevalence estimates and adjusted odds ratios (AORs).Endnote 20, Endnote 21 The bootstrap method randomly samples, with replacement from the original set of observations, to obtain a sampling distribution for a population parameter. We conducted all analyses with a SASEndnote 22 macro developed by methodologists at Statistics Canada; it was based on a total of 500 samples, as recommended by the software developers.
Table 1 shows the sociodemographic characteristics of the study population. Missing data were minimal (< 1%). FN and Inuit populations were younger than the non-Aboriginal population; 59% and 74% of FN and Inuit, respectively, were aged less than 45 years compared to 50% of the non-Aboriginal population. The age structure of the Métis population is similar to the non-Aboriginal population. Educational attainment is lower among Aboriginal populations compared to the non-Aboriginal population. Annual income is also lower for FN and Inuit populations compared to the Métis and non-Aboriginal populations.
Variability in chronic disease and risk factor prevalence was found among FN, Inuit and Métis residents of northern Canada. Most research and chronic disease surveillance reports for northern Canada have, to date, combined the three ethnic groups into one–Aboriginal–group. However, the three groups have different histories, cultural backgrounds and lifeways, all of which may have influenced the differences in outcomes and will affect interventions to address them.
Among the Inuit, prevalence of chronic disease was lower than among the northern FN and Métis populations. This is consistent with previous findings related to diabetes,Endnote 23, Endnote 24 although inter-ethnic differences regarding other chronic diseases have not been investigated. Lix et al. previously reported on the prevalence of chronic disease and risk factors for southern Aboriginal people (i.e. residents of the 10 Canadian provinces) using 2005/2006 CCHS data.Endnote 4 Compared to Aboriginal populations in southern Canada, the prevalence of arthritis, asthma, heart disease, diabetes and high blood pressure is lower among the Inuit. Prevalence of chronic disease risk factors is more variable. The Inuit were similar to northern FN and Métis on most of the risk factors investigated in this research. However, compared to southern Aboriginal populations, the Inuit have lower prevalence of overweight and regular drinking but similar levels of obesity and higher prevalence of binge drinking and daily smoking.Endnote 4
We previously also reported on chronic disease and risk factor prevalence among northern Aboriginal and non-Aboriginal populations by territory of residence (i.e. NWT, Yukon and Nunavut).Endnote 8 The prevalence of most chronic disorders among the Inuit has not increased and risk factor prevalence has stayed the same or increased, compared to Aboriginal data for Nunavut. Specifically, prevalence of overweight and obesity has not changed, but daily smoking, regular drinking and binge drinking have increased.Endnote 8
That the prevalence of chronic disease among the Inuit remains the lowest for all Aboriginal people in Canada and has generally not increased since 2000 is positive. This may be attributable to greater adherence to traditional lifestyles including dietary patterns among this group. However, the literature also suggests the beginning of a shift to western diets.Endnote 25 On the other hand, the increasing prevalence of risk factors among the Inuit is worrying. The risk factors that are increasing are linked to major chronic diseases such as cancerEndnote 26 and heart diseaseEndnote 27 and social problems like violence, accidents, injuries, addictions, and family and community dysfunction.Endnote 28 This finding, together with other reported adverse changes in the health transition,Endnote 29, Endnote 30 suggests that some chronic conditions could be on the rise. Communities, clinicians and policy makers must work together to address the increasing risk factors and develop interventions aimed at risk factor reduction.
Among northern FN residents, prevalence of arthritis, asthma and heart disease is lower than among southern Aboriginal people, of diabetes is about the same, and of high blood pressure is greater.Endnote 4 The picture for chronic disease risk factors is also variable. Compared to southern Aboriginal residents, FN residents in northern Canada have similar prevalence of overweight, obesity and regular drinking but higher prevalence of binge drinking and daily smoking.Endnote 4 The chronic disease and risk factor picture for northern FN people is of concern because it has been seen before among FN people in southern Canada; chronic diseases and risk factors among Aboriginal people of southern Canada are sources of excess morbidity, decreased quality of life and premature mortality.
Finally, prevalence of arthritis, asthma and heart disease among the Métis of northern Canada is lower than among Métis of southern Canada.Endnote 31, Endnote 32, Endnote 33 Compared to southern Aboriginal Canadians, the prevalence of overweight is similar, daily smoking is lower, but obesity, regular drinking and binge drinking are higher. Similar to the Inuit and northern FN, the risk factor profile of the Métis is of concern because of cardiometabolic morbidity, social consequences and premature mortality.
It will be important for northern Aboriginal communities and organizations to work with government agencies and health care professionals to decrease the risk profile if they hope to avert the epidemic of cardiometabolic conditions witnessed among Aboriginal people in southern Canada. However, the environment in the north may be more challenging because community resources are fewer, food more expensive and the effects of climate change greater.Endnote 34, Endnote 35
Strengths and limitations
This study is subject to limitations. CCHS data are based on self-report; this may result in underestimates of chronic disease and risk factors such as BMI, smoking and drinking. Further, commonly used cutpoints of BMI for obesity and overweight may not be appropriate for all Aboriginal populations.Endnote 36 Respondents may also overestimate their overall levels of physical activity. Dietary data, although relevant to chronic disease, could not be included because these data were collected as part of an optional module of the CCHS. CCHS data apply only to Aboriginal people living off-reserve and therefore miss the entire segment of those living on-reserve. However, FN, Inuit and Métis populations in the Yukon and Nunavut do not live on reserve; nor do over 99% of the FN people in NWT.Endnote 5 As such, our sample is a good representation of Aboriginal people in northern Canada. There are, however, limitations of the identification of Aboriginal people in the CCHS.Endnote 37 Pooling cycles of the CCHS, specifically the issue of re-sampling the same individuals and sample dependence is also a limitation. Lastly, the large number of comparisons may contribute to a greater likelihood of significant chance findings.
Notwithstanding these limitations, this research represents an important contribution on the health of Aboriginal peoples in Canada's north. This research is the first to compare northern FN, Inuit and Métis on chronic disease and risk factor prevalence. We found significant differences in disease and risk factors among these three Aboriginal groups. Ethnicspecific data are important to Aboriginal political organizations, government policy makers, clinicians and communities because they offer the chance to set priorities for interventions. While some results are heartening, the risk factor profile among all three northern Aboriginal populations is of concern. Continued chronic disease and risk factor surveillance will be important to monitor continued changes over time and to evaluate the impact of public health interventions.
This study was supported by the Canadian Institutes of Health Research. None of the authors have a conflict of interest.