Geographic variation in health care and the problem of measuring racial disparities.

In its study of racial and ethnic disparities in health care, the Institute of Medicine (IOM) concluded that there were large and significant disparities in the quality and quantity of health care received by minority groups in the United States. This article shows that where a patient lives can itself have a large impact on the level and quality of health care the patient receives. Since black or Hispanic populations tend to live in different areas from non-Hispanic white populations, location matters in the measurement and interpretation of health (and health care) disparities. There is wide variation in racial disparities across geographic lines: some areas have substantial disparities, while others have equal treatment. Furthermore, there is no consistent pattern of disparities: some areas may have a wide disparity in one treatment but no disparity in another. The problem of differences in quality of care across regions, as opposed to racial disparities in care, should remain the target of policy makers, as reducing quality disparities would play a major role in improving the health care received by all Americans and by minority Americans in particular.