Causal connections between socio-economic status and health: reciprocal effects and mediating mechanisms.

Using structural equation modeling techniques on data from a nationally representative longitudinal survey, we first explored the reciprocal relationships between socio-economic status (SES) and health status. We then estimated the degree to which health-related lifestyles/behaviors and psychosocial distress are mediating mechanisms of these relationships. As predicted, SES positively affects health, and health positively affects SES. Although the causal path from SES to health is stronger than the reverse, these findings confirmed the hypothesis that both social causation and health selection contribute to social inequalities in health. In terms of the mediating mechanisms through which SES and health affect each other, more than a third of the overall SES-health relationship was accounted for by health-related lifestyles/behaviors and psychosocial distress. A notable part of the effect of SES on health is due to differences in psychological distress, with the effects of health-related lifestyles/behaviors being much smaller. On the other hand, in terms of the effects of health on SES, differences in weight and sleeping behavior are more important than psychological distress.