The Canadian Census Health and Environment Cohorts (CanCHECs) are population-based probabilistically linked datasets. The CanCHECs combine long-form census respondents (or National Household Survey (NHS) respondents) with administrative health data (e.g. mortality, cancer, hospitalizations, ambulatory care) and annual mailing address postal codes. These data can be used to examine health outcomes by population characteristics measured by the long-form census or NHS (e.g. income, education, occupation, language, ethnicity, immigrant status, or Indigenous identity). Environmental data can be attached to the CanCHECs using the annual postal code file in order to examine the association between environmental exposure and a health outcome.
The CanCHEC linkages were approved by Statistics Canada's senior management (Microdata linkage approval number 019-2019) and are governed by the Directive on Microdata Linkage.
Socio-economic and ethno-cultural data
1991, 1996, 2001 and 2006 long-form censuses
The census of population is conducted once every five years to provide a detailed statistical portrait of Canada and its people by their demographic, social, and economic characteristicsFootnote 1. The long-form census questionnaire is sent to approximately one in five Canadian households and includes information regarding relationships, languages, labour, income, education, housing, and ethnic origin. Only people who were counted by the long-form census were eligible for 1991, 1996, 2001, and 2006 CanCHEC inclusion.
2011 National Household Survey
The 2011 National Household SurveyFootnote 2 was a voluntary survey that was sent to approximately one in three Canadian households and includes information regarding relationships, languages, labour, income, education, housing, and ethnic origin. Only people who were counted by the 2011 National Household Survey were eligible for 2011 CanCHEC inclusion.
Health outcome data
Canadian Vital Statistics Death Database
The Canadian Vital Statistics Death DatabaseFootnote 3 (CVSD) is an administrative survey that collects demographic and cause of death information annually from all provincial and territorial vital statistics registries on all deaths in Canada. Death data are received from the province or territory where the death occurred. Cause of death information is coded using the version of the International Classification of Diseases (ICD) in effect at the time of death. The CanCHEC cohorts only include those deaths up until December 31, 2016 that were successfully linked to cohort members.
Canadian Cancer Registry
The Canadian Cancer RegistryFootnote 4 (CCR) is a national, dynamic, population-based registry that includes information about each new primary cancer diagnosed in cohort members since 1992. The CanCHEC cohorts only includes those CCR records up until December 31, 2015 (up until December 31, 2010 in the province of Quebec) that were successfully linked to cohort members.
Discharge Abstract Database
The Discharge Abstract DatabaseFootnote 5 (DAD) includes administrative, clinical, and demographic information for all acute care (and some psychiatric, chronic rehabilitation, and day-surgery) hospital discharges for all province and territories, except Quebec. Only the 2006 and 2011 CanCHEC cohorts include DAD records; these span from April 1, 2000 to March 31, 2016.
National Ambulatory Care Reporting System
The National Ambulatory Care Reporting SystemFootnote 6 (NACRS) contains data for hospital-based and community-based ambulatory care including day surgery, outpatient and community-based clinics, and emergency departments. Client visit data are collected at time of service in the participating facilities from several jurisdictions. Only the 2006 and 2011 CanCHEC cohorts include NACRS records; these span from April 1, 2002 to March 31, 2017.
Postal Code file
Annual postal codes
Income tax returns are the principal data source for the annual postal code file. Postal codes from the mailing addresses provided by filers when submitting their T1 tax file were extracted and used to estimate a person's place of residence for that reference year. Note that for some tax filers, the mailing addresses used for filing T1 tax records may not be associated with their place of residenceFootnote 7.
|1991 CanCHEC||1996 CanCHEC||2001 CanCHEC||2006 CanCHEC||2011 CanCHEC|
|Data source||1991 mandatory long-form census||1996 mandatory long-form census||2001 mandatory long-form census||2006 mandatory long-form census||2011 voluntary National Household Survey|
|Number of cohort members||2.6 million||3.6 million||3.5 million||5.9 million||6.5 million|
|Minimum age (years) of cohort members on census day||25||19||19||0||0|
|Years of available annual postal codesTable note *||1981-2016||1981-2016||1981-2016||1981-2016||1981-2016|
|Years of follow-up for mortality||1991-2016||1996-2016||2001-2016||2006-2016||2011-2016|
|Years of follow-up for cancer incidenceTable note **||1992-2015||1992-2015||1992-2015||1992-2015||1992-2015|
|Years of follow-up for hospital dischargesTable note ***||2000/01 to 2016/17||2000/01 to 2016/17|
|Years of follow-up for ambulatory careTable note ****||2002/03 to 2017/18||2002/03 to 2017/18|