Clinician Specialties, Quality Score and Shared Savings Receipt in Accountable Care Organizations

Objective To assess the relationship between the changing Accountable Care Organizations‐ACO workforce and ACOs' shared savings earnings and quality performance. Data Sources Medicare Shared Savings Program‐MSSP provider‐level research identifiable files, performance year financial and quality report public use files, and National Physician Compare data (2013–2021). Study Setting and Design We characterized 865 MSSPs, separately pre‐ (2013–2019) and post‐pandemic (2020–2021) according to the percentage of primary care physicians (PCPs), non‐physicians, specialists, and other specialty, financial risk model, assigned Medicare beneficiary demographics, clinical risk factors, and provider supply by specialty within the MSSP's primary service state, (total and per‐capita) shared savings earnings/losses owed and quality score. Longitudinal ordinary least‐squares regressions with random effects were estimated to assess the association between MSSP provider specialty mix and annual (1) per‐capita shared savings/losses and (2) quality score, controlling for risk model, beneficiary characteristics, provider supply, and year factors. We also compared outcomes across MSSPs, 32 Pioneers and 62 Next Generation‐NGACOs. Principal Findings PCPs represented 33.9% of MSSP's workforce, on average. Higher percentages of PCPs and non‐physicians were associated with higher per‐capita earned shared savings and quality scores among MSSPs. A 1‐percentage‐point (ppt) increase in PCPs and non‐physicians was associated with higher per‐capita shared savings of $2.25 ( p < 0.01) and $1.82 ( p = 0.03), respectively, pre‐COVID, and $2.73 ( p < 0.01) and $1.81 ( p = 0.14) post‐COVID. We estimated increases in quality scores among MSSPs of ~0.1 ppt with a 1 ppt increase in PCPs, non‐physicians, and specialists only pre‐pandemic. No statistically significant relationships were estimated between provider specialty mix and performance measures in Pioneers and NGACOs. Conclusions Higher percentages of PCPs and non‐physicians were associated with higher per‐capita shared savings earnings and quality scores among MSSPs. As new federal initiatives continue to unfold, value‐based payment models increasing incentives for primary care should be monitored to determine their ability to further improve care efficiency.