在考虑非随机退出因素后，医疗保险共享储蓄计划中的表现：一项工具变量分析。
Performance in the Medicare Shared Savings Program After Accounting for Nonrandom Exit: An Instrumental Variable Analysis.
机构信息
University of Michigan Medical School and School of Public Health, Ann Arbor, Michigan (A.A.M.).
University of Michigan Medical School and Institute for Healthcare Policy and Innovation, Ann Arbor, Michigan (J.M.H.).
出版信息
Ann Intern Med. 2019 Jul 2;171(1):27-36. doi: 10.7326/M18-2539. Epub 2019 Jun 18.
BACKGROUND
Accountable care organizations (ACOs) in the Medicare Shared Savings Program (MSSP) are associated with modest savings. However, prior research may overstate this effect if high-cost clinicians exit ACOs.
OBJECTIVE
To evaluate the effect of the MSSP on spending and quality while accounting for clinicians' nonrandom exit.
DESIGN
Similar to prior MSSP analyses, this study compared MSSP ACO participants versus control beneficiaries using adjusted longitudinal models that accounted for secular trends, market factors, and beneficiary characteristics. To further account for selection effects, the share of nearby clinicians in the MSSP was used as an instrumental variable. Hip fracture served as a falsification outcome. The authors also tested for compositional changes among MSSP participants.
SETTING
Fee-for-service Medicare, 2008 through 2014.
PATIENTS
A 20% sample (97 204 192 beneficiary-quarters).
MEASUREMENTS
Total spending, 4 quality indicators, and hospitalization for hip fracture.
RESULTS
In adjusted longitudinal models, the MSSP was associated with spending reductions (change, -$118 [95% CI, -$151 to -$85] per beneficiary-quarter) and improvements in all 4 quality indicators. In instrumental variable models, the MSSP was not associated with spending (change, $5 [CI, -$51 to $62] per beneficiary-quarter) or quality. In falsification tests, the MSSP was associated with hip fracture in the adjusted model (-0.24 hospitalizations for hip fracture [CI, -0.32 to -0.16 hospitalizations] per 1000 beneficiary-quarters) but not in the instrumental variable model (0.05 hospitalizations [CI, -0.10 to 0.20 hospitalizations] per 1000 beneficiary-quarters). Compositional changes were driven by high-cost clinicians exiting ACOs: High-cost clinicians (99th percentile) had a 30.4% chance of exiting the MSSP, compared with a 13.8% chance among median-cost clinicians (50th percentile).
LIMITATION
The study used an observational design and administrative data.
CONCLUSION
After adjustment for clinicians' nonrandom exit, the MSSP was not associated with improvements in spending or quality. Selection effects-including exit of high-cost clinicians-may drive estimates of savings in the MSSP.
PRIMARY FUNDING SOURCE
Horowitz Foundation for Social Policy, Agency for Healthcare Research and Quality, and National Institute on Aging.
背景
医疗保险共享储蓄计划（MSSP）中的问责医疗组织（ACO）与适度的储蓄相关。然而，如果高成本临床医生退出 ACO，先前的研究可能会夸大这种影响。
目的
在考虑临床医生非随机退出的情况下，评估 MSSP 对支出和质量的影响。
设计
类似于先前的 MSSP 分析，本研究通过调整纵向模型，将 MSSP ACO 参与者与对照受益人的数据进行了比较，该模型考虑了长期趋势、市场因素和受益人的特征。为了进一步考虑选择效应，使用 MSSP 附近临床医生的比例作为工具变量。髋部骨折被用作验证结果。作者还测试了 MSSP 参与者的组成变化。
设置
按服务付费的医疗保险，2008 年至 2014 年。
患者
20%的样本（97204192 个受益季度）。
测量指标
总支出、4 项质量指标和髋部骨折住院治疗。
结果
在调整后的纵向模型中，MSSP 与支出减少（变化，每受益季度减少 118 美元[95%CI，-151 至-85]）和所有 4 项质量指标的改善相关。在工具变量模型中，MSSP 与支出（变化，每受益季度增加 5 美元[CI，-51 至 62]）或质量无关。在验证测试中，MSSP 在调整模型中与髋部骨折相关（每 1000 个受益季度减少 0.24 次髋部骨折住院治疗[CI，-0.32 至-0.16 次]），但在工具变量模型中不相关（每 1000 个受益季度增加 0.05 次住院治疗[CI，-0.10 至 0.20 次]）。组成变化是由高成本临床医生退出 ACO 驱动的：高成本临床医生（第 99 个百分位数）退出 MSSP 的可能性为 30.4%，而中等成本临床医生（第 50 个百分位数）的可能性为 13.8%。
局限性
该研究使用了观察性设计和行政数据。
结论
在调整临床医生非随机退出后，MSSP 与支出或质量的改善无关。选择效应——包括高成本临床医生的退出——可能会影响 MSSP 储蓄的估计。
主要资金来源
霍洛威茨社会政策基金会、医疗保健研究与质量局和国家老龄化研究所。
Zotero 插件