Department of Health Care Policy and Management, Harvard T.H. Chan School of Public Health, 677 Huntington Ave, Kresge 411, Boston, MA 02115. Email:
Am J Manag Care. 2018 May 1;24(5):e141-e149.
Reducing leakage to outside specialists has been promoted as a key strategy for accountable care organizations (ACOs). We sought to examine changes in specialty care leakage and use associated with the Medicare Shared Savings Program (MSSP).
Analyses of trends in ACOs from 2010 to 2014 and quasi-experimental difference-in-differences analyses comparing changes for ACOs versus local non-ACO providers from before until after the start of ACO contracts, stratified by ACO specialty composition and year of MSSP entry.
We used Medicare claims for a 20% sample of beneficiaries attributed to ACOs or non-ACO providers. The main beneficiary-level outcome was the annual count of new specialist visits. ACO-level outcomes included the proportion of visits for ACO-attributed patients outside of the ACO (leakage) and proportion of ACO Medicare outpatient revenue devoted to ACO-attributed patients (contract penetration).
Leakage of specialist visits decreased minimally from 2010 to 2014 among ACOs. Contract penetration also changed minimally but differed substantially by specialty composition (85% for the most primary care-oriented quartile vs 47% for the most specialty-oriented quartile). For the most primary care-oriented quartile of ACOs in 2 of 3 entry cohorts, MSSP participation was associated with differential reductions in new specialist visits (-0.04 visits/beneficiary in 2014 for the 2012 cohort; -5.4%; P <.001). For more specialty-oriented ACOs, differential changes in specialist visits were not statistically significant.
Leakage of specialty care changed minimally in the MSSP, suggesting ineffective efforts to reduce leakage. MSSP participation was associated with decreases in new specialty visits among primary care-oriented ACOs.
减少向外部专家的漏诊一直被视为问责制医疗组织（ACO）的关键策略。我们试图研究与医疗保险共享储蓄计划（MSSP）相关的专业护理漏诊和使用的变化。
对 2010 年至 2014 年 ACO 的趋势进行分析，并对 ACO 与当地非 ACO 提供者进行准实验差异分析，比较 ACO 合同开始前后的变化，根据 ACO 专科构成和 MSSP 参与年份进行分层。
我们使用医疗保险索赔对 20%的 ACO 或非 ACO 提供者的受益人群进行了抽样。主要的受益层面结果是每年新专科就诊的次数。ACO 层面的结果包括 ACO 归因患者在 ACO 外就诊的比例（漏诊）和 ACO 医疗保险门诊收入中用于 ACO 归因患者的比例（合同渗透率）。
ACO 中专家就诊的漏诊率从 2010 年到 2014 年略有下降。合同渗透率也略有变化，但专科构成差异很大（最以初级保健为导向的四分位数为 85%，最以专科为导向的四分位数为 47%）。在 3 个入组队列中的 2 个最以初级保健为导向的 ACO 四分位数中，MSSP 参与与新专科就诊的差异减少相关（2012 队列中 2014 年每受益人次减少 0.04 次就诊；-5.4%；P<.001）。对于更以专科为导向的 ACO，专科就诊的差异变化不具有统计学意义。
MSSP 中专科护理的漏诊变化不大，表明减少漏诊的努力效果不佳。MSSP 参与与以初级保健为导向的 ACO 中新专科就诊次数的减少相关。
