The authors calculated national rates of hospitalization for avoidable conditions by age, race, median income of zip code, and insurance status using 1990 data from the National Hospital Discharge Survey, the National Health Interview Survey, and the census. Such conditions were viewed as an indicator of equity and efficiency in the US health care system.

Results indicated that Blacks and persons living in middle- or lower-income areas had higher rates of potentially avoidable hospitalizations than Whites and persons living in high-income areas. However, differences among income and racial groups for persons aged 65 and older were not significant.

The authors postulated that such findings in persons aged 65 and older are a result of increased access to primary care due to Medicare. The authors also note that “Blacks may experience increased barriers to ambulatory care at each median income group.” In particular, “social conditions in the central areas of particular older cities, where many Blacks and minority groups reside, suggest alternative explanations—urban decay and racism—which may be affecting the association of race with both median income of zip code of residence and quality of health care.”