Methods for Measuring Racial Differences in Hospitals Outcomes Attributable to Disparities in Use of High-Quality Hospital Care.

OBJECTIVE: To compare two approaches to measuring racial/ethnic disparities in the use of high-quality hospitals. DATA SOURCES: Simulated data. STUDY DESIGN: Through simulations, we compared the "minority-serving" approach of assessing differences in risk-adjusted outcomes at minority-serving and non-minority-serving hospitals with a "fixed-effect" approach that estimated the reduction in adverse outcomes if the distribution of minority and white patients across hospitals was the same. We evaluated each method's ability to detect and measure a disparity in outcomes caused by minority patients receiving care at poor-quality hospitals, which we label a "between-hospital" disparity, and to reject it when the disparity in outcomes was caused by factors other than hospital quality. PRINCIPAL FINDINGS: The minority-serving and fixed-effect approaches correctly identified between-hospital disparities in quality when they existed and rejected them when racial differences in outcomes were caused by other disparities; however, the fixed-effect approach has many advantages. It does not require an ad hoc definition of a minority-serving hospital, and it estimated the magnitude of the disparity accurately, while the minority-serving approach underestimated the disparity by 35-46 percent. CONCLUSIONS: Researchers should consider using the fixed-effect approach for measuring disparities in use of high-quality hospital care by vulnerable populations.