Cause-specific mortality by education in Canada: a 16-year follow-up study.

Background: People with lower levels of education tend to have higher rates of disease and death, compared with people who have higher levels of education. However, because death registrations in Canada do not contain information on the education of the deceased, unlinked vital statistics cannot be used to examine mortality differentials by education.

Methods: This study examines cause-specific mortality rates by education in a broadly representative sample of Canadians aged 25 or older. The data are from the 1991 to 2006 Canadian census mortality follow-up study, which included about 2.7 million people and 426,979 deaths. Age-standardized mortality rates (ASMRs) were calculated by education for different causes of death. Rate ratios, rate differences and excess mortality were also calculated.

Results: All-cause ASMRs were highest among people with less than secondary graduation and lowest for university degree-holders. If all cohort members had the mortality rates of those with a university degree, the overall ASMRs would have been 27% lower for men and 22% lower for women. The causes contributing most to that "excess" mortality were ischemic heart disease, lung cancer, chronic obstructive pulmonary disease, stroke, diabetes, injuries (men), and respiratory infections (women). Causes associated with smoking and alcohol abuse had the steepest gradients.

Interpretation: A mortality gradient by education was evident for many causes of death.