Surgical Outcomes and Medicare Advantage Payer-Hospital Integration.

Importance: Hospitals are increasingly offering their own insurance plans through payer-hospital integration, including Medicare Advantage (MA) plans. Whether MA payer-hospital integration can improve surgical care through aligned incentives is unknown. Objective: To assess postsurgical outcomes between differing levels of exposure to MA payer-hospital integration. Design, Setting, and Participants: This serial cross-sectional study included inpatient MA admissions for colectomy, coronary artery bypass grafting, cystectomy, hysterectomy, peripheral bypass, pulmonary lobectomy, total hip arthroplasty, and total knee arthroplasty between 2015 and 2022. MA payer-hospital integration was identified using data from the Agency for Healthcare Research and Quality compendium files, verification of hospital and plan websites, and public MA plan data. Data analysis was conducted between December 1, 2024, and March 1, 2025. Exposure: MA insurance coverage was categorized as either nonintegrated (enrolled in a non-hospital-owned MA plan), partially integrated (enrolled in a hospital-owned MA plan but surgical procedure performed at nonaffiliated hospital), or fully integrated (enrolled in a hospital-owned MA plan and surgical procedure performed at the hospital that owns the MA plan). Main Outcomes and Measures: The primary outcome was inpatient postoperative complications. Secondary outcomes included postoperative inpatient serious complications, length of stay, intensive care unit (ICU) use, and readmission, which were assessed using multivariable generalized linear models adjusting for patient demographic and clinical characteristics and hospital's and patient's county fixed effects. Results: A total of 560 499 inpatient surgical admissions were included, with 373 506 nonintegrated, 109 695 partially integrated, and 77 298 fully integrated admissions. The mean (SD) age of those admitted was 73.4 (7.6) years; 320 161 (57.1%) were women; and 490 460 (87.5%) were non-Hispanic White, 46 665 (8.3%) were non-Hispanic Black, and 8556 (1.5%) were other race and/or ethnicity. Compared with nonintegrated admissions, fully integrated admissions had significantly lower rates of any complications (-0.36 percentage points; 95% CI, -0.59 to -0.12 percentage points), serious complications (-0.31 percentage points; 95% CI, -0.51 to -0.10 percentage points), any ICU use (-1.1 percentage points; 95% CI, -1.73 to -0.46 percentage points), and shorter length of stay (-0.32 days; 95% CI, -0.39 to -0.25 days). Compared with partially integrated admissions, fully integrated admissions had lower rates of serious complications (-0.25 percentage points; 95% CI, -0.49 to -0.01 percentage points), any ICU use (-1.25 percentage points; 95% CI, -1.96 to -0.55 percentage points), and shorter length of stay (-0.38 days; 95% CI, -0.48 to -0.28 days). There was no significant difference in complications or readmission between fully and partially integrated admissions. Conclusions and Relevance: The findings suggest that enrolling in a hospital-owned MA plan and undergoing a surgical procedure at the affiliated hospital were associated with improved postsurgical outcomes. As MA enrollment continues to grow, these findings have important implications for health care policy, suggesting that aligned incentives and coordinated care delivery between insurers and hospitals may help improve surgical outcomes.