Race/ethnicity and 30-day readmission rates in medicare beneficiaries with COPD

BACKGROUND: COPD is now included in Medicare’s hospital readmission reduction program. Hospitals with excessive risk-adjusted 30-d readmission rates receive financial penalties. Race/ethnicity is not included in the risk-adjustment models. We examined whether race/ethnicity was independently associated with readmission after controlling for clinical factors and other demographic variables. METHODS: We used the 100% Medicare in-patient (Part A) files to identify patients hospitalized with COPD (MS-DRG codes 190, 191, 192) who were discharged between January 1, 2013, and September 13, 2014. The outcome measure was an unplanned readmission within 30 d of hospital discharge. We used generalized linear mixed models to test the independent effects of race/ethnicity on 30-d readmission. RESULTS: The sample included 298,706 Medicare beneficiaries hospitalized for COPD: 87% white, 8% African-American, and 5% Hispanic. Mean age was 77.7 = 7.7 y. Overall, 17.3% of subjects experienced an unplanned readmission. Whites (17.4%) and African-Americans (17.7%) had significantly higher unadjusted rates than Hispanics, and Hispanics demonstrated the lowest readmission rate (16.3%). The minority groups generally displayed higher-risk clinical profiles. After controlling for those differences, the multivariable model suggested a benefit for both minority groups in terms of readmission risk. The adjusted readmission rates for whites, African-Americans, and Hispanics were 16.6%, 15.9%, and 14.6%, respectively. CONCLUSIONS: Racial/ethnic disparities in observed readmission rates may be largely explained by the more severe clinical profiles of minority populations. Controlling for known clinical risk factors effectively mediates the relationship between race/ethnicity and readmission.