This study investigates the degree to which the relationship between self-rated health and mortality is consistent across income groups in Canada and whether it can be explained by differentials in physical activity.
A sample of 17,852 adults in the 1981 Canada Fitness Survey was followed for 13 y for mortality.
After adjusting for several confounders, there was a dose-response relationship between self-rated health and all-cause, CVD, and cancer mortality. This relationship persisted across levels of income. Physical activity was inversely related to mortality; however, the risk of mortality associated with low self-rated health did not differ significantly between activity groups.
Physical activity does not appear to be a significant mediating or moderating factor in the relationship between self-rated health and mortality.