Linking the Canadian Community Health Survey and the Canadian Mortality Database: An enhanced data source for the...

This study summarizes the linkage of the Canadian Community Health Survey (CCHS) and the Canadian Mortality Database (CMDB), which was performed to examine relationships between social determinants, health behaviours and mortality in the household population.

The 2000/2001-to-2011 Canadian Community Health Surveys were linked to the 2000-to-2011 CMDB using probabilistic methods based on common identifiers (names, date of birth, postal code and sex) for eligible respondents (85%; n = 614,774). Mortality records from January 1, 2000 through December 31, 2011 for people aged 12 or older were eligible for linkage (n = 2.774 million). The linkage was enhanced with information from the Historical Tax Summary File. Quality assessment consisted of internal and external validation. Cox survival analysis (age-adjusted) was conducted to estimate hazard ratios (HRs) associated with selected health behaviours.

Overall, 5.3% of eligible CCHS respondents linked to a mortality record; false positive and false negative rates were 0.04% and 2.43%, respectively. Linkage rates were higher among males (5.8%) and people aged 75 or older (20.2%), reflecting known mortality risks. Survival analyses confirmed elevated mortality risk associated with heavy (HR 2.36, CI 1.84, 2.89) and light smoking (HR 1.91, CI 1.52, 2.33), compared with not smoking; underweight and obesity, compared with normal and overweight; low fruit and vegetable consumption; and lack of physical activity.

Linking health behaviour information from the CCHS to mortality data from the CMDB allows for a greater understanding of modifiable determinants of mortality.