Effects of Medicare Part D on Racial/Ethnic Disparities in Hospital Utilization Among Seniors.

OBJECTIVE

The aim of this study is to evaluate whether Medicare Part D reduced racial/ethnic disparities in hospital utilization among Medicare seniors, based on the Institute of Medicine's definition of a disparity.

METHOD

Using data on 43,098 adult respondents to the 2002-2009 Medical Expenditure Panel Survey, we derive a difference-in-difference-in-differences estimator using a multivariate regression framework, and measure Part D's effects on disparities in any hospitalization, the number of nights hospitalized, and inpatient expenses.

RESULTS

Part D narrowed racial/ethnic disparities in hospital utilization. For African Americans, it reduced the disparity in any hospitalization by 2.94% (p < .001) but had no effect on disparities in nights hospitalized or inpatient expenses. For Hispanics, Part D reduced disparities in nights hospitalized by 1.58 nights (p = .009) and in inpatient expenses by US$3,453 (p < .001).

DISCUSSION

Following Medicare Part D, disparities in hospital utilization narrowed significantly for both African American and Hispanic seniors, but in different ways for each population.