Derek Lake, Postdoctoral Research Associate, Department of Health Services, Policy & Practice
Abstract Title: The Effect of Medicare Advantage Enrollment on Post-Acute Care Utilization and Associated Patient Outcomes
Abstract: Prior research indicates that compared to Traditional Medicare (TM.) beneficiaries, Medicare Advantage (MA) enrollees utilize less intense and fewer days of post-acute care (PAC) following hospitalization, without experiencing worse patient outcomes. However, existing comparisons of PAC utilization and patient outcomes between the MA and TM populations are likely biased by non-random selection of Medicare beneficiaries into MA plans. In this study I estimate the effect of MA enrollment relative to TM enrollment on PAC utilization and associated patient outcomes following hospital discharge. I exploit the expansion of MA enrollment between 2012 and 2017 as a natural experiment in a difference-in-differences analysis using cross-temporal matching to examine changes in outcomes associated with MA enrollment. This study includes Medicare beneficiaries hospitalized for stroke (N=177,322) or hip fracture (N=144,119). MA enrollment was associated with fewer IRF discharges for stroke (-8.5 pp) and hip fracture (-13.4pp) cases, and increased discharges to SNF for hip fracture cases (+9.0 pp) and home for stroke cases (+8.2 pp). Changes in PAC episodes were characterized by increased SNF days (stroke: 1.4 days; fracture: 3.2 days), and fewer days of IRF (stroke: -1.3 days; fracture: -1.9 days) and home health (stroke: -3.1 days; fracture: -4.6 days). MA enrollees experienced lower rates of (180-day) hospital readmission (stroke: -2.8 pp; fracture -2.1 pp), and more days at home (stroke: 6.1 days; fracture: 6.1 days). Mortality risk was similar among stroke patients, though hip fracture patients enrolled in MA experienced increased mortality at thirty (0.8pp) and ninety days (1.2pp) post-hospitalization. These findings indicate that among Medicare beneficiaries recovering from hip fracture and stroke, those enrolling in MA plans utilize fewer days of PAC services in less expensive settings of care. Though these efficiency gains coincide with modest improvements in patient outcomes for stroke patients, MA enrollees hospitalized with hip fracture may face increased risk of mortality.