Hospital Readmissions to Nonindex Hospitals: Patterns and Determinants Following the Medicare Readmission Reduction Penalty Program

OBJECTIVE: To examine patterns and determinants of nonindex readmissions for Medicare as well as non-Medicare patients both before and immediately after the adoption of Medicare's Hospital Readmission Reduction Program (HRRP) in 2012. Nonindex readmissions are readmissions to hospitals that are different from the one from which the patient was discharged. METHODS: Observational analysis of statewide database from California comprising patient-level discharge reports. Mixed-effects logistic regression models examined the association between nonindex readmissions and both hospital- and patient-level characteristics. RESULTS: Nonindex readmissions for the population studied were approximately 25%, but the percentage of such readmissions was significantly higher for non-Medicare patients than those enrolled in Medicare. Nonindex readmissions were associated with several patient- and hospital-level characteristics from which patients were discharged. The adoption of the HRRP did not have any appreciable impact on the general pattern of nonindex readmissions. CONCLUSIONS: A substantial percentage of hospital readmissions are to nonindex hospitals, but the general pattern and determinants of these events have not changed following the adoption of the HRRP. As preventable readmissions continue to gain attention as a key quality indicator for hospital care, further investigations are needed to understand the potential value of nonindex readmissions as a quality indicator for hospital care.