A total of 654 participants died during the 24-year follow-up period. The researchers found that in the analyses adjusted for sex and year of birth, those with the lowest socioeconomic position had a 1.6 times higher risk of death from all causes than those with the highest socioeconomic position. Overall, health behaviors assessed at baseline explained 42 percent of the association between socioeconomic position and all-cause mortality; this increased to 72 percent when they were entered as time-dependent covariates (a variable that is possibly predictive of the outcome under study). All health behaviors taken together at baseline explained 29 percent of the gradient for cardiovascular mortality and 45 percent when they were entered as time-dependent covariates. These figures for noncancer and noncardiovascular mortality were 61 percent and 94 percent, respectively.

"The difference between the baseline only and repeated assessments of health behaviors was mostly due to an increased explanatory power of diet, physical activity, and alcohol consumption. The role of smoking, the strongest mediator in these analyses, did not change when using baseline or repeat assessments," the researchers write.

"This study suggests that health behaviors explain a substantial part of social inequalities in mortality and demonstrates the importance of taking into account changes over time in health behaviors when examining their role in social inequalities."

"Our findings may not necessarily have straightforward policy implications. On the one hand, the findings imply that health policies and interventions focusing on individual health behaviors have the potential not only to increase the population's health but also to substantially reduce inequalities in health. On the other hand, if health behaviors are socially patterned and determined, for example, by financial factors, the capacity to respond to health education messages, or the environment in which they live, the same policies aimed at improving the population's health may contribute to an increase in social inequalities in health," the authors conclude.

SOURCE JAMA