Racial/Ethnic Disparities in Readmissions in US Hospitals: The Role of Insurance Coverage

Background:A better understanding of the key drivers of population-level differences in readmissions, particularly by race/ethnicity, can inform the development of interventions at the practice and policy levels to reduce overall inappropriate readmissions. One of the major factors that could contribute to readmission risks by racial/ethnic groups is the insurance status of patients. In this study, we examine differences in rates of 30-day readmissions across patients by race/ethnicity, and the extent to which these differences were mediated by insurance coverage.

Study Design: We use hospital discharge data of patients in the 18 and above age group for 5 US states, California, Florida, Missouri, New York, and Tennessee for 2009, obtained from the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases (SID) of the Agency for Healthcare Research and Quality, linked to contextual and provider data from Health Resources and Services Administration. We used random effects logistic regression models by state to estimate the association between insurance status, race, and the likelihood of a readmission within thirty days of an index hospital admission for any cause, controlling for patient severity, other patient characteristics, and hospital and community attributes. In order to assess whether readmission rates of racial ethnic minorities vary with their insurance status, additional analysis including interactions between race and insurance status is conducted.

Findings:

African Americans overall experienced a higher risk of readmissions compared to whites, although findings varied by state. The odds ratios of interactions do indicate considerable heterogeneity in this risk among African Americans stratified by insurance; compared to those on private insurance, those uninsured (OR=0.86) or on Medicaid (OR=0.95) or other payer (OR=0.93, all p values < 0.05) had significantly lower risk of readmission, but those on Medicare had similar risk. A similar pattern was found for Hispanics. Overall, risk of readmission was lower for Hispanics, compared to whites, but among Hispanics, those on Medicaid, other payer or uninsured had lower risk of readmissions (OR=0.75, 0.81, 0.73, all p values < 0.05) compared to those on private insurance, while those on Medicare had relatively higher readmission risk (OR=1.11, p<0.05). Other race-ethnic group also exhibited heterogeneity in readmission risk, with lower risk among the uninsured (OR=0.88) and higher risk among Medicare-covered (OR=1.15, p values < 0.05) compared to those on private insurance. These patterns were largely consistent across all individual states.

Conclusion: Using comprehensive discharge data including all age groups under different insurance coverages, we found that for all three minority groups (African Americans, Hispanics and Other), private or Medicare coverage was associated with higher risk of readmissions than that for absence of insurance coverage, or coverage under Medicaid or other coverage. Overall Hispanics and Others had lower risk of readmission compared to non-Hispanic whites, while African Americans had higher risk of readmission.

 Policy Implications: The study shows that risk of readmissions by racial ethnic groups varies by insurance status. The lower risk of 30-day readmissions among racial ethnic minorities could be a reflection of their inadequate insurance coverage, and not necessarily their better health condition or better post-discharge care.