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.
Mason is with the School of Physical and Health Education, Queen’s University, Kingston, ON; Katzmarzykis with the School of Physical and Health Education and the Department of Community Health and Epidemiology, Queen’s University, Kingston, ON; Craig is with Canadian Fitness and Lifestyle Research Institute, Ottawa, and the Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON; Gauvin is with the Départment de médecine sociale et preventive and GRIS—Groupe de recherché interdiscipline en santé, Université de Montréal, Montréal, as well as the Léa-Roback Research Center on Social Inequalities of Health of Montréal, Montréal, QC.