The effect of primary care physician supply and income inequality on mortality among blacks and whites in US metropolitan areas.

OBJECTIVES This study assessed whether income inequality and primary care physician supply have a different effect on mortality among Blacks compared with Whites. METHODS We conducted a multivariate ecologic analysis of 1990 data from 273 US metropolitan areas. RESULTS Both income inequality and primary care physician supply were significantly associated with White mortality (P < .01). After the inclusion of the socioeconomic status covariates, the effect of income inequality on Black mortality remained significant (P < .01), but the effect of primary care physician supply was no longer significant (P > .10), particularly in areas with high income inequality. CONCLUSIONS Improvement in population health requires addressing socioeconomic determinants of health, including income inequality and primary care availability and access.