Association of Physician Group Practice Participation in Bundled Payments With Patient Selection, Costs, and Outcomes for Joint Replacement.

Importance: Medicare's Bundled Payments for Care Improvement (BPCI) program, which ran from 2013 to 2018, was an important experiment in physician-focused alternative payment models. However, little is known about whether the program was associated with better quality or outcomes or lower costs. Objective: To determine whether participation in BPCI among physician group practices was associated with advantageous or deleterious changes in costs or patient outcomes. Design Setting and Participants: This cross-sectional study used 2013 to 2017 Medicare files and difference-in-differences (DID) models to compare the change over time in Medicare payments, patient selection, and clinical outcomes between 91 orthopedic groups in BPCI Model 2 and 169 propensity-matched controls for patients undergoing joint replacement. Analyses were performed between December 2019 and February 2021. Exposures: Voluntary participation in BPCI. Main Outcomes and Measures: The primary outcome was 90-day Medicare payments; secondary outcomes were patient selection (volume, comorbidities) and clinical outcomes (30-day and 90-day emergency department visits, readmissions, mortality, and healthy days at home). Results: There were 74 343 patient episodes in the baseline period and 102 790 during the intervention in BPCI practices, and 88 147 patient episodes in the baseline period and 120 253 during the intervention in control practices; 291 214 of 461 598 (63.1%) patients were women, and 419 619 (90.9%) were White. At baseline, mean episode payments among BPCI-participating practices were $18 257, which decreased to $15 320 during the intervention, while control practices decreased from $17 927 to $16 170 (DID, -$1180; 95% CI, -$1565 to -$795; Conclusions and Relevance: Group practice participation in BPCI for joint replacement was associated with reduced Medicare payments and improvements in clinical outcomes.