Health behaviours and health: evidence that the relationship is not conditional on income adequacy

This study used Canadian data to examine whether the relationships between two health behaviours (physical activity and smoking) and two measures of health (self-perceived health status and number of chronic health conditions) are conditional on income adequacy. Studies that have investigated the manner in which socioeconomic circumstances, such as income adequacy, and health behaviours interact to influence health are few in number and characterized by inconsistent findings. In addition, there is a complete absence of published Canadian research that has explored these relationships. I investigated the relationship between health behaviours and health by income adequacy with a secondary analysis of data from the first cycle of the National Population Health Survey (NPHS), conducted by Statistics Canada in 1994-95. The sample consisted of 11,941 NPHS respondents 20-64 years of age who did not have an illness or disability that prevented them from being employed. As a whole, findings from a series of hierarchical multiple regression analyses did not provide adequate evidence to conclude that the effects of physical activity and smoking on self-perceived health status and chronic health conditions are conditional on income adequacy. Instead, findings showed that the health behaviours each had a similar degree of influence on the self-perceived health status and number of chronic health conditions of respondents at all income adequacy levels. Moreover, the magnitude of the relationships between the health behaviours and health measures was very small. By enhancing knowledge about both the nature and magnitude of the relationships among Canadians' income adequacy, health behaviours, and health, this study makes a significant contribution to the small body of research that has explored the possibility that the relationship between health behaviours and health varies by socioeconomic circumstances. I conclude the paper with a discussion of the implications that the findings have for public health policies and programs.