Income inequality, primary care, and health indicators

BACKGROUND. The significant association of income inequality with a variety of health indicators is receiving increasing attention. There has also bee n increasing evidence of a link between primary care and improved health st atus. We examined the joint relationship between income inequality, availab ility of primary care, and various health indicators to determine whether p rimary care has an impact on health indicators by modifying the adverse eff ect of income inequality. METHODS. Our ecologic study used the US states as the units of analysis. In analyzing the data, we looked at the associations among income inequality, primary care, specialty care, smoking, and health indicators, using Pearso n's correlation coefficients for intercorrelations and the adjusted multipl e regression procedure. To examine the effect of inequality and primary car e on health outcome indicators, we conducted path analyses according to a c ausal model in which inequality affects health both directly and indirectly through its impact on primary care. RESULTS. Our study indicates that both primary care and income inequality e xerted a strong and significant direct influence on life expectancy and tot al mortality (P <.01). Primary care also exerted a significant direct influ ence on stroke and postneonatal mortality (P <.01). Although levels of smok ing are also influential, the effect of income inequality and primary care persists after controlling for smoking. Primary care serves as one pathway through which income inequality influences population-level mortality and a t least some other health outcome indicators. CONCLUSIONS. It appears possible that a primary care orientation may, in pa rt, overcome the severe adverse effects on health of income inequalities.