Factors Associated With Participation in Cardiac Episode Payments Included in Medicare's Bundled Payments for Care Improvement Initiative.

Importance: Medicare's Bundled Payments for Care Improvement (BPCI) is a voluntary pilot program evaluating bundled payments for several common cardiovascular conditions. Evaluating the external validity of this program is important for understanding the effects of bundled payments on cardiovascular care. Objective: To determine whether participants in BPCI cardiovascular bundles are representative of US acute care hospitals and identify factors associated with participation. Design, Setting, and Participants: Retrospective cross-sectional study of hospitals participating in BPCI model 2 bundles for acute myocardial infarction (AMI), congestive heart failure (CHF), coronary artery bypass graft, and percutaneous coronary intervention and nonparticipating control hospitals (October 2013 to January 2017). The BPCI participants were identified using data from the Centers for Medicare and Medicaid Services, and controls were identified using the 2013 American Hospital Association's Survey of US Hospitals. Hospital structural characteristics and clinical performance data were obtained from the American Heart Association survey and Centers for Medicare and Medicaid Services. One hundred fifty-nine hospitals participating in BPCI model 2 cardiac bundles and 1240 nonparticipating control hospitals were compared, and a multivariable logistic regression was estimated to identify predictors of BPCI participation. Exposures: Bundled payments. Main Outcomes and Measures: Hospital-level structural characteristics and 30-day risk-adjusted readmission and mortality rates for AMI and CHF.
Results: Compared with nonparticipants, BPCI participants were larger, more likely to be privately owned or teaching hospitals, had lower Medicaid bed day ratios (ratio of Medicaid inpatient days to total inpatient days: 17.0 vs 19.3; P < .001), and were less likely to be safety net hospitals (2.5% vs 12.3%; P < .001). The BPCI participants had higher AMI and CHF discharge volumes, were more likely to have cardiac intensive care units and catheterization laboratories, and had lower risk-standardized 30-day mortality rates for AMI (13.7% vs 16.6%; P = .001) and CHF (11.3 vs 12.4; P = .005). In multivariable analysis, larger hospital size and access to a cardiac catheterization laboratory were positively associated with participation. Being a safety net hospital was negatively associated with participation (odds ratio, 0.3; 95% CI, 0.1-0.7; P = .001). Conclusions and Relevance: Hospitals participating in BPCI model 2 cardiac bundles differed in significant ways from nonparticipating hospitals. The BPCI outcomes may therefore have limited external validity, particularly among small and safety net hospitals with limited clinical cardiac services.