Surgeon Participation in Early Accountable Care Organizations

Objective: We aimed to characterize the landscape of surgeon participation in early accountable care organizations (ACOs) and to identify specialty-, organization-, and market-specific factors associated with ACO participation. Background: Despite rapid deployment of alternative payment models (APMs), little is known about the prevalence of surgeon participation, and key drivers behind surgeon participation in APMs. Methods: Using data from SK&A, a research firm, we evaluated the near universe of US practices to characterize ACO participation among 125,425 US surgeons in 2015. We fit multivariable logistic regression models to characterize key drivers of ACO participation, and more specifically, the interaction between ACO affiliation and organizational structure. Results: Of 125,425 US surgeons, 27,956 (22.3%) participated in at least 1 ACO program in 2015. We observed heterogeneity in participation by subspecialty, with trauma and transplant reporting the highest rate of ACO enrollment (36% for both) and plastic surgeons reporting the lowest (12.9%) followed by ophthalmology (16.0%) and hand (18.6%). Surgeons in group practices and integrated systems were more likely to participate relative to those practicing independently (aOR 1.57, 95% CI 1.50, 1.64; aOR 4.87, 95% CI 4.68, 5.07, respectively). We observed a statistically significant interaction (P < 0.001) between surgical specialty and practice organization. Model-derived predicted probabilities revealed that, within each specialty, surgeons in integrated health systems had the highest predicted probabilities of ACO and those practicing independently generally had the lowest. Conclusions: We observed considerable variation in ACO enrollment among US surgeons, mediated at least in part by differences in practice organization. These data underscore the need for development of frameworks to characterize the strategic advantages and disadvantages associated with APM participation.