Factors Associated With Disparities in Hospital Readmission Rates Among US Adults Dually Eligible for Medicare and Medicaid

Abstract

IMPORTANCE Low-income older adults who are dually eligible (DE) for Medicare and Medicaid often experience worse outcomes following hospitalization. Among other federal policies aimed at improving health for DE patients, Medicare has recently begun reporting disparities in withinhospital readmissions. The degree to which disparities for DE patients are owing to differences in community-level factors or, conversely, are amenable to hospital quality improvement, remains heavily debated. OBJECTIVE To examine the extent to which within-hospital disparities in 30-day readmission rates for DE patients are ameliorated by state-and community-level factors. DESIGN, SETTING, AND PARTICIPANTS In this retrospective cohort study, Centers for Medicare & Medicaid Services (CMS) Disparity Methods were used to calculate within-hospital disparities in 30-day risk-adjusted readmission rates for DE vs non-DE patients in US hospitals participating in Medicare. All analyses were performed in February and March 2019. The study included Medicare patients (aged Ն65 years) hospitalized for acute myocardial infarction (AMI), heart failure (HF), or pneumonia in 2014 to 2017. MAIN OUTCOMES AND MEASURES Within-hospital disparities, as measured by the rate difference (RD) in 30-day readmission between DE vs non-DE patients following admission for AMI, HF, or pneumonia; variance across hospitals; and correlation of hospital RDs with and without adjustment for state Medicaid eligibility policies and community-level factors. RESULTSThe final sample included 475 444 patients admitted for AMI, 898 395 for HF, and 1 214 282 for pneumonia, of whom 13.2%, 17.4%, and 23.0% were DE patients, respectively. Dually eligible patients had higher 30-day readmission rates relative to non-DE patients (RD >0) in 99.0% (AMI), 99.4% (HF), and 97.5% (pneumonia) of US hospitals. Across hospitals, the mean (IQR) RD between DE vs non-DE was 1.00% (0.87%-1.10%) for AMI, 0.82% (0.73%-0.96%) for HF, and 0.53% (0.37%-0.71%) for pneumonia. The mean (IQR) RD after adjustment for community-level factors was 0.87% (0.73%-0.97%) for AMI, 0.67% (0.57%-0.80%) for HF, and 0.42% (0.29%-0.57%) for pneumonia. Relative hospital rankings of corresponding within-hospital disparities before and after community-level adjustment were highly correlated (Pearson coefficient, 0.98). CONCLUSIONS AND RELEVANCEIn this cohort study, within-hospital disparities in 30-day readmission for DE patients were modestly associated with differences in state Medicaid policies and community-level factors. This suggests that remaining variation in these disparities should be the focus of hospital efforts to improve the quality of care transitions at discharge for DE patients in efforts to advance equity.

Measuring Equity in Readmission as a Distinct Assessment of Hospital Performance

“…We demonstrated variation in performance on our equitable readmission measure, suggesting potential for improvement at the hospital level. Although patient- and community-level factors influence risk of readmission, prior work demonstrating differential readmission rates for the same patients, with similar risk factors at different hospitals, indicates that hospital quality independently contributes to readmission risk . Furthermore, prior work has demonstrated that variation in readmission disparities for dual-eligible beneficiaries remains even when controlling for state Medicaid policy, health service availability, and social factors .…”

“…Although patient- and community-level factors influence risk of readmission, prior work demonstrating differential readmission rates for the same patients, with similar risk factors at different hospitals, indicates that hospital quality independently contributes to readmission risk . Furthermore, prior work has demonstrated that variation in readmission disparities for dual-eligible beneficiaries remains even when controlling for state Medicaid policy, health service availability, and social factors . By this logic, inequities in readmission rates are also likely driven by hospital factors, some fixed, but some modifiable to improve inequities in care.…”

“…We chose variables based on a conceptual model delineating potential hospital-level factors that influence equitable readmissions (eFigure 1 in Supplement 1) as well as prior work examining drivers of readmissions, readmission disparities, and overall quality . In this study, we focused on hospital-level factors that are relatively fixed with the goal of characterizing hospitals with equitable readmissions.…”

The Relative Importance of Hospital Discharge and Patient Composition in Changing Post-Acute Care Utilization and Outcomes Among Medicare Beneficiaries

“…Second, changes in patient composition also resulted in changes in PAC utilization (ie, admissions across PAC facility types), especially via hospital discharge patterns (ie, to home vs various types of PAC facilities). The changes in hospital discharge patterns and the overall PAC utilization during the pandemic could come from at least 3 sources: (1) changes that can be explained by the patient demographics and clinical characteristics in general (eg, sicker patients need more intensive treatment) 6 – 8 ; (2) changes that can be explained by the differential effects of patient-level characteristics during the pandemic relative to the previous period (eg, patients living alone were even more likely to use PACthan those who were living with others during the pandemic than before) 21 – 25 ; (3) changes during the pandemic that are independent of patient characteristics (eg, changes in care delivery and practice). 15 , 18 These sources of variation and the relative contribution to the overall PAC utilization changes are not well understood.…”

“…Third, we expect that changes in PAC utilization will result in changes in patient health outcomes and future healthcare costs both short- and long-term. 5 , 21 , 22 Yet, there has been very limited research on this relationship thus far. Short-term responses in health outcomes may include changes in mortality and hospital readmissions.…”