Retracing the history of the early development of national chronic disease surveillance in Canada and the major role of the Laboratory Centre for Disease Control (LCDC) from 1972 to 2000
B. C. K. Choi, PhD (1, 2); D. T. Wigle, MD, PhD (2); H. Johansen, PhD (2, 4); J. Losos, MD, DECH, FRCP(C), FACPM (2, 3); M. E. Fair, MSc (4); E. Napke, MD, DPH (2); L. J. Anderson, BA (2, 5); J. W. Davies, MBBS, DPH, FFPHM (2, 3); K. White, BA, BEd (2, 4); A. B. Miller, MD, FRCP, FRCP(C) (6); F. C. K. Li, MBBS, FRCP(C) (2, 7); S. Stachenko, MD (1, 8); J. Lindsay, PhD (2, 3); L. A. Gaudette, MSc (1, 4); C. Nair, MA (4, 9); I. Levy, MBBCh, FRCP(C) (2, 10); H. Morrison, PhD (1, 2); J. Silins, MHA (2, 4); F. Bouchard, MD, FRCP(C) (2, 11); L. Tonmyr, PhD (1, 2); P. J. Villeneuve, PhD (2, 12); L. McRae, BSc (1, 2); K. C. Johnson, PhD (1, 2); R. S. D. Lane, MSc (2, 13); A. Probert, MSc (2)
- Public Health Agency of Canada, Ottawa, Ontario, Canada
- Health Canada, Ottawa, Ontario, Canada
- University of Ottawa, Ottawa, Ontario, Canada
- Statistics Canada, Ottawa, Ontario, Canada
- Health and Social Policy Editing Consultant, Ottawa, Ontario, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Embassy of Canada, Beijing, China
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Health Information Solutions, Ottawa, Ontario, Canada
- Ottawa Public Health, Ottawa, Ontario, Canada
- Nunavik Regional Board of Health and Social Services, Kuujjuaq, Quebec, Canada
- Carleton University, Ottawa, Ontario, Canada
- Canadian Nuclear Safety Commission, Ottawa, Ontario, Canada
Correspondence: Dr. Bernard Choi, Senior Research Scientist, Public Health Agency of Canada, 785 Carling Avenue, PL# 6806B, Ottawa, Ontario, Canada K1A 0K9; Tel: 613-957-1074; Fax: 613-941-2057; Email: Bernard.Choi@phac-aspc.gc.ca
The 1918 federal Statistics ActFootnote 4 created the Dominion Bureau of Statistics (DBS, called Statistics Canada as of 1971) with a mandate to collect and publish statistical information.
The 1919 Department of Health Act created the Department of Health.Footnote 5 In 1937, the Epidemiology Division was formed in what was then the Department of Pensions and National Health, but was dissolved during World War II, and re-established in 1947 with a focus on infectious diseases. When the Health Protection Branch (HPB) was created within the Department of National Health and Welfare (DNHW) in 1972, the Epidemiology Division was renamed the Bureau of Epidemiology and merged with the much larger Canadian Communicable Disease Centre (formerly called the Division of Laboratories and Medical Research, established in 1921, and renamed the Laboratory of Hygiene in 1925)Footnote 2 to form the new the Laboratory Centre for Disease Control (LCDC). In 1972-1973, LCDC's Bureau of Epidemiology initiated the surveillance of cancer and cardiovascular diseases. Surveillance activities for cancer used provincial cancer registry data, while those for cardiovascular disease relied on survey and mortality data.6,7 In 1995, three bureaus were created in LCDC--the Cancer Bureau, the Bureau of Reproductive and Child Health (BRCH) and the Bureau of Cardio-Respiratory Diseases and Diabetes (BCRDD).Footnote 8
In 2000, Health Canada was reorganized, and LCDC was combined with the Health Promotion and Programs Branch (HPPB) to create a new branch, the Population and Public Health Branch (PPHB).Footnote 9 In 2004, PPHB was reorganized and became part of the Public Health Agency of Canada (PHAC).
Figure 1 summarizes the organizational evolution of the federal health departments, branches and directorates that relate to the development of national chronic disease surveillance in Canada.
Besides Health Canada and PHAC, two other major organizations that contribute to national chronic disease surveillance are Statistics Canada and Canadian Institute for Health Information (CIHI).
A brief history of major initiatives for chronic disease
surveillance in Canada
The Nova Scotia-Saskatchewan Cardiovascular Disease Mortality Study (NSSCDMS) was a collaborative surveillance project initiated in 1984 by the Bureau of Epidemiology. This study produced the first population-based estimates of acute myocardial infarction incidence, recurrence and survival in Canada.Footnote 10 Existing administrative data sets were used for surveillance purposes through record linkage, linking hospital admission/separation records with mortality data, and thus creating person-oriented information for the first time.Footnote 11
Important provincial partnerships with the Canadian Heart Health Initiative (CHHI) (1986-1995) of the Health Promotion Directorate supported standardized risk factor surveys in the provinces, including both behavioural and biological measures, and paved the way for the future work in Canada. In 1986, the first provincial heart health survey was conducted in Nova Scotia. Eventually, all 10 provinces undertook heart health surveys between 1986 and 1995. Through home interviews and clinic visits, the heart health surveys collected information and physical measures on cardiovascular risk factors as well as knowledge of the causes and consequences of cardiovascular disease.Footnote 12
The National Cancer Incidence Reporting System (NCIRS) was initiated in 1972 by Statistics Canada in collaboration with the National Cancer Institute of Canada and Health and Welfare Canada. Eventually, data were collected back to 1969 from all of the provincial and territorial cancer registries. In 1974, the Bureau of Epidemiology formed a section to accelerate analysis of national cancer incidence and mortality data. The Canadian Cancer Registry (CCR) was established in 1992. The person-oriented CCR was developed over 10 years from 1988 to 1998, and starting with data from 1992, featured internal record linkage to remove duplicates and death clearance to permit calculation of survival rates. As of 1987, Canadian Cancer Statistics provides annual ongoing national surveillance of trends as well as current year estimates of the cancer burden.
In 1992, the Bureau of Chronic Disease Epidemiology (BCDE) initiated the Canadian Childhood Cancer Control Program (CCCCP). BCDE worked with the 21 pediatric oncology centres in Canada to collect childhood cancer data with detailed patient information that allowed for enhanced surveillance and etiological research.Footnote 13
In 1992-1994, the Cancer Bureau participated in the Great Lakes Basin Cancer Risk Assessment Study (GLBCRAS) in collaboration with the Environmental Health Directorate of the Health Protection Branch (HPB) and Environment Canada. The Division contracted the University of Toronto and the Ontario Cancer Treatment and Research Foundation (OCTRF) to study the effect of chlorinated drinking water on the development of bladder and colon cancers.Footnote 14,Footnote 15
In collaboration with the Health Programs and Services Branch of Health Canada, the BCDE established the Canadian Breast Cancer Screening Database (CBCSD) in 1993 to monitor and evaluate organized breast cancer screening programs.
Between 1994 and 1997, LCDC conducted the National Enhanced Cancer Surveillance System (NECSS) in collaboration with the provincial cancer registries, collecting detailed risk factor information by questionnaire from a Canada-wide sample of over 20 000 patients diagnosed with one of 19 types of cancer and over 5000 population-based control subjects.Footnote 16 The Environmental Quality Data Base (EQDB) was developed in parallel to link with the subjects' residential histories and aid research on the relationships between cancer and measures of industrial activity, and air and drinking water quality.
In 1987, the Bureau of Chronic Disease Epidemiology (BCDE) began the surveillance of asthma morbidity and mortality using Statistics Canada's national databases.Footnote 17 After detecting an epidemic of asthma deaths among Canadians aged 15 to 34 years, BCDE convened a national workshop in 1987 that stimulated research on asthma and highlighted the need for improved asthma treatment. In 1993, an asthma program was established in BCDE.
In 1995, the BCRDD, in partnership with national medical and health professional associations, established the National Asthma Control Task Force (NACTF) to reduce asthma morbidity and mortality in Canada. Between 1995 and 2000 the NACTF developed the National Asthma Prevention and Control Strategy. To collect necessary data for formulation of effective asthma intervention strategies, an asthma supplement survey was incorporated into the National Population Health Survey (NPHS) in 1995.
The Student Lung Health Survey (SLHS; 1995-1996), a school-based survey of children aged 5 to 19 years in nine voluntary health units across Canada, was part of a Sentinel Health Unit Surveillance System.Footnote 18 BCRDD conducted the Physician Asthma Management Survey (PAMS; 1996-1997) to identify physicians' practices in Canada.Footnote 19,Footnote 20
BCRDD initiated the National Diabetes Surveillance System (NDSS) in 1996. The NDSS was the first such system to use provincial data on physician encounters and hospitalizations to calculate disease prevalence. NDSS was a network of regionally distributed diabetes surveillance systems that compiled administrative health care data relating to diabetes and sent aggregate anonymous data to Health Canada for national analyses. In 2009, NDSS expanded into the Canadian Chronic Disease Surveillance System (CCDSS) with the addition of hypertension, asthma and other chronic disease surveillance.
Child and maternal health
The thalidomide disaster in 1961 caused 115 known cases of severe birth defects during 1961 and 1962.Footnote 21 As a result, Department of National Health and Welfare (DNHW) established the Voluntary Drug Adverse Reaction Reporting Program (VDARRP) in 1965. In 1966, the Child and Maternal Health Division started a pilot system of birth-defects surveillance in 4 provinces (British Columbia, Alberta, Manitoba and New Brunswick),Footnote 22 and in 1966, the Congenital Anomalies Surveillance System (CASS) was established. By 1989, the system included Alberta, Manitoba, Ontario, New Brunswick, Nova Scotia, Prince Edward Island and the Northwest Territories, while British Columbia had stopped submitting data.Footnote 23 Newfoundland joined in 2004.Footnote 24 This was the first national purpose-built surveillance system based on vital statistics data.
In 1989, the BCDE collaborated with the Canadian Pediatrics Society to initiate the Children's Hospitals Injury Research and Prevention Program (CHIRPP). CHIRPP became the Canadian Hospitals Injury Reporting and Prevention Program in 1991. In 1995, the Canadian Perinatal Surveillance System (CPSS) was initiated to collect and analyze data on all recognized pregnancies and on the health of the baby during the first year of life. This is an ongoing national surveillance program, now delivered through PHAC. In 1996, the Bureau of Reproductive and Child Health (BRCH) initiated a child maltreatment surveillance program, the Canadian Incidence Study of Reported Child Abuse and Neglect (CIS), which collects data from all Canadian jurisdictions.Footnote 25
Starting in 1993, Statistics Canada provided the Canadian Birth Data Base (CBDB) and the Canadian Stillbirth Data Base (CSDB) with data from 1985 onward, in response to the ongoing need for the Canadian Perinatal Surveillance System and other uses.Footnote 26,Footnote 27
In 1989, the BCDE collaborated with the University of Ottawa to initiate 3 phases of the Canadian Study of Health and Aging (CSHA), designed to measure the incidence and prevalence of Alzheimer's disease and other dementias and explore potential causal factors on a national scale.Footnote 28 The CSHA operated in 18 centres across all provinces and, in 1991 to 1992, recruited over 10 000 seniors who participated in screening interviews, a risk factor questionnaire, a clinical examination and clinical tests.Footnote 29,Footnote 30
Cost of illness
The Economic Burden of Illness in Canada (EBIC) is an analysis of the direct and indirect costs of illness in Canada. LCDC published the first EBIC report with 1986 data in 1991,Footnote 31 and again with 1993 data in 1997.Footnote 32 The 1998 data were published online.Footnote 33
The first EBIC report provides comprehensive and authoritative estimates of the cost of illness in Canada. These estimates are vital to setting priorities for allocating limited health resources. The second report improved significantly on the first, providing estimates of the direct and indirect costs of illness in Canada by age and sex. To research and write the third report, LCDC staff collaborated with their colleagues in Statistics Canada, CIHI and Health Canada to provide information by cost component (direct and indirect), diagnostic category, age, sex and province/territory.Footnote 33 The project was moved from LCDC's Cancer Bureau to the Bureau of Policy and Planning, and is now managed by PHAC.
Surveys and administrative databases
National surveying of chronic diseases was in its infancy in Canada when the LCDC was formed in 1972. Early surveys included the Canadian Sickness Survey (1950-1951), the Survey of Smoking Habits (supplements to the Labour Force Survey) (1966-1975) and the Nutrition Canada Survey (1970-1972).Footnote 34
In the 1970s, LCDC and Statistics Canada developed data infrastructure to monitor national chronic disease trends and to facilitate the conduct of major epidemiology (cohort) studies. The computerized Canadian Mortality Data Base (CMDB) was initiated to facilitate record linkage to national death records (from 1950 onwards) for a major cohort studyFootnote 35 after the National Cancer Institute of Canada provided a small subvention. The NCIRS (from 1969 onward) was used not only for surveillance but also to evaluate screening programs, to conduct cohort studies and, eventually, for survival analysis.Footnote 36,Footnote 37 With the process of record linkage pioneered by Newcombe,Footnote 38,Footnote 39 utilizing these databases was facilitated by the development of a Generalized Iterative Record Linkage System (GIRLS).Footnote 40,Footnote 41
Since the Canada Health Survey was conducted in 1978 to 1979, more surveys have become available. Examples include the General Social Surveys (1985-), the Health and Activity Limitations Survey (1983-), the Heart Health Surveys (1986-1995), the National Population Health Survey (1994-) and the National Longitudinal Survey of Children and Youth (1995-).Footnote 34 The Canadian Community Health Survey (2000-) and the Canadian Health Measures Survey (2007-) are the most recent national health surveys relevant to chronic disease surveillance.
In 1998, LCDC collaborated with Cancer Care Ontario, Ontario Ministry of Health and Durham Regional Health Authority to set up a steering committee on risk factor surveillance at the local level. In 1999, a pilot project was conducted in the Durham health region to test the concept and a prototype of a rapid risk factor surveillance system at the local level. The pilot project, which proved to be a success,Footnote 42 subsequently led to the Rapid Risk Factor Surveillance System (RRFSS) still in operation in Ontario today.
A significant achievement in science was the Canadian invention of the world's first protocol for computerized record linkage. Methodological research on computerized record linkages arose out of the necessity to link individuals' records from different databases. The LCDC conducted this research in collaboration with Statistics Canada and the National Cancer Institute of Canada (NCIC) Epidemiology Unit at the University of Toronto.Footnote 26,Footnote 38,Footnote 39,Footnote 40,Footnote 43,Footnote 44,Footnote 45,Footnote 46 In the mid-1970s, the GIRLS was developed to facilitate cohort studies.Footnote 40,Footnote 41 From 1978 to 2000, LCDC funded several occupational and environmental health research projects involving record linkage.Footnote 27,Footnote 47,Footnote 48
Although record linkage was initially to assess risk, it has become a valuable tool for surveillance. The NDSS (1996-2009) and the subsequent CCDSS (2009-) rely heavily on record linkage. Computerized record linkage is now widely used across Canada and around the world.
In 1980, LCDC started a journal, Chronic Diseases in Canada (CDIC) (1980-2011), which was renamed Chronic Diseases and Injuries in Canada (CDIC) in 2011 and Health Promotion and Chronic Disease Prevention in Canada: Research, Policy and Practice in 2015. In 1989, the Health Statistics Division of Statistics Canada initiated its new journal, Health Reports (HR) (1989-). Both journals publish peer-reviewed articles on chronic disease epidemiology, public health, biostatistics, behavioural sciences, health services and health economics. Many disease and topic-specific publications have also been produced by the former LCDC, PHAC, Statistics Canada and CIHI.
In 1996, LCDC officially launched its website to provide public health information online. Moving into the electronic age, the general public has benefited greatly from online information products such as Disease Surveillance On-Line and Injury Surveillance On-Line. Since 2000, Health Indicators has been produced jointly by Statistics Canada and CIHI . An online publication, Health Indicators is a compilation of indicators measuring health status, non-medical determinants of health, health-system performance, and community and health-system characteristics.
National chronic disease surveillance has a critical role in determining trends in chronic diseases. Surveillance enables governments and stakeholders to monitor the effects of public health interventions and project health resource requirements. The basic question is, what effect has surveillance information and activities had on improving the health of Canadians? Surveillance is only a means to an end. Surveillance is useful only if the results can be applied to reduce morbidity and suffering, save lives and improve the quality of life of the population.
The disease surveillance work in Canada has helped improve a number of health conditions. The decline in lung cancer cases was partly due to the surveillance and epidemiology work on tobacco use that provided the basis for a major push in the tobacco area. Some LCDC scientists were recognized as expert witnesses in court cases on tobacco. Cancer incidence and mortality data were used to prioritize and evaluate cancer control programs, such as screening for breast and colorectal cancer. The British Columbia Health Surveillance Registry was used early on to assess genetic risk,Footnote 49,Footnote 50 and these data have been quoted in several subsequent reports from official international committees concerned with the potential health risks of exposure to ionizing radiation.Footnote 51,Footnote 52 Other examples of impact on policy and programs include reduced mortality in cardiovascular disease, asthma and many forms of cancer, increased use of folic acid in relation to heart disease, and increased supplementation of food in relation to hydrocephalus and spinal bifida. The discovery in the childhood injury surveillance program of unusual occurrences was useful in generating modifications to baby cribs to prevent further accidents.
This article retraces the history of the development of national chronic disease surveillance in Canada from 1960 to 2004. Our aim was to describe the early milestones in the development and operation of national public health surveillance in Canada. We hope that this will lead to an appreciation of the need for surveillance and act as a catalyst for progress.
We thank the 126 former staff of the LCDC at Health Canada and of Statistics Canada and the National Cancer Institute of Canada, who had participated in national chronic disease surveillance in Canada during 1960-2000, for their assistance in acquiring historical data, in many cases from their own historical records, early publications, unpublished personal transcripts and memory. We gratefully acknowledge peer reviews and constructive comments by a large number of colleagues at the Public Health Agency of Canada.