Peripheral artery disease is independently associated with impaired function, an increased risk of mortality, and decreased quality of life. Supervised exercise therapy (SET) reduces symptoms and improves walking performance, and is recommended in consensus guidelines.¹ Historically, lack of reimbursement for SET greatly limited access and utilization.² However, in May 2017, the Centers for Medicare & Medicaid Services (CMS) determined that the evidence was sufficient to cover SET for beneficiaries with intermittent claudication. Although this provided remuneration to create new SET programs and expand existing ones, data are scant on the utilization of and outcomes associated with SET since CMS’ reimbursement decision. This study aimed to address this lack of data by utilizing Medicare beneficiary data.

The data that support the findings of this study are available from the corresponding author upon reasonable request. The study was approved by the institutional review board of Beth Israel Deaconess Medical Center. Patients with a Current Procedural Terminology code for SET or International Classification of Diseases, Tenth RevisionClinical Modification code for intermittent claudication required by CMS for SET reimbursement between June 1, 2017 (corresponding with CMS’ reimbursement agreement) and December 31, 2018, in the 100% CMS Institutional Outpatient File were included. Baseline characteristics and comorbidities were obtained via a 1-year look back in the MedPAR, Carrier, and Chronic Condition Warehouse files. Outcomes included all-cause death, lower extremity revascularization, and hospitalization for myocardial infarction, congestive heart failure, or stroke through December 31, 2018.

Patients were divided by the presence or absence of a SET Current Procedural Terminology code. Categorical variables were reported as frequencies and proportions and compared with χ² or Fisher exact tests, as appropriate. To account for baseline differences between patients, the propensity score for receiving SET was calculated for each patient using all baseline characteristics. Each SET patient was then matched using the propensity score to the three nearest unexposed patients. Cox regression was then used to evaluate the association between SET and outcomes in the matched population. Fine-Gray methods were used to account for the competing risk of death for nondeath outcomes. All P<0.05 were considered significant.

Among 129 699 patients with a diagnosis of intermittent claudication, 1735 (1.3%) were enrolled in SET during the study period. The median number of SET sessions attended was 16 (interquartile range, 6–28), and 89 patients (5.1%) completed the program (36 sessions). Compared with those not enrolled (n=127 964), SET patients were slightly older (73.6±8.0 years versus 73.1±9.1 years), more likely to be White (87.2% versus 84.0%), and less likely to be Black (8.8% versus 10.9%), dually enrolled in Medicaid (12.7% versus 22.4%), and female (39.0% versus 42.5%) (Table). A majority of patients enrolled in SET were from the Midwest (48.1%) and Northeast (16.1%) regions of the United States. Only 9.2% and 12.6% of SET patients were from the South Atlantic and South regions of the United States, respectively. In comparison, patients from the South Atlantic and South regions comprised of 18.2% and 21.1% of the non-SET group, respectively.

Table. Patient Characteristics and Outcomes Stratified by SET Referral

Characteristics of and 1-year cumulative incidences in all SET vs non-SET patients and the propensity score–matched cohorts. SET indicates supervised exercise therapy.

SET patients were followed for a median of 153 days (interquartile range, 77–252 days) and non-SET patients were followed for a median of 244 days (interquartile range, 130–362 days). The 1-year cumulative incidence of endovascular and surgical revascularization among patients participating in SET were 11.9% and 2.4%, respectively (Table). No patients undergoing SET underwent amputation during the follow-up period. In the matched cohort analysis (n=6940 patients), the use of endovascular or surgical revascularization was significantly lower among those who underwent SET (endovascular: hazard ratio, 0.49 [95% CI, 0.40–0.60], P<0.001; surgical: hazard ratio, 0.27 [95% CI, 0.18–0.42], P<0.001). There were no other differences in outcomes between groups (Table).

In this study of Medicare beneficiaries with symptomatic peripheral artery disease, we found very low utilization of SET during the first 19 months after approval by CMS despite a Class IA guideline endorsement.¹ In fact, the referral rate was similar to data from the PORTRAIT (Patient-centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) registry that preceded reimbursement approval.³ Patients referred to SET differed in race, sex, socioeconomic status, and geographic region compared with those unenrolled, suggesting disparities emerging early during implementation. Participation in SET once enrolled was limited, with few patients completing the full program.

These data highlight the greater effort that is needed to increase SET enrollment across the United States, as well as to improve adherence once enrolled. Strategies to accomplish this may include greater efforts to educate both providers and patients of the benefits of SET, investment in broadening the regional availability and total number of SET programs, and consideration of novel extensions of SET (via telerehabilitation, for example). Overall, a multifaceted approach will be needed to dramatically increase utilization. Furthermore, there needs to be a focus on ensuring that all patients with peripheral artery disease, irrespective of race, geographic region, or socioeconomic status, have access to this guideline-recommended treatment.

Limitations of this study include the small number of patients referred to SET, the low event rates and the short follow-up time, the possibility of treatment selection bias and residual confounding, the inability to assess severity of symptoms due to the use of claims codes, and the lack of detail regarding SET protocols.

This work was funded by the Smith Center for Outcomes Research in Cardiology. Dr Divakaran is supported by a joint KL2/Catalyst Medical Research Investigator Training (CMeRIT) award from Harvard Catalyst and the Boston Claude D. Pepper Older Americans Independence Center (5P30AG031679-10). Dr Secemsky is supported by National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute (NHLBI) K23 HL150290 and Harvard Medical School’s Shore Faculty Development Award.

Disclosures None.

For Sources of Funding and Disclosures, see page 916.

外周动脉疾病与功能受损、死亡风险增加和生活质量下降独立相关。有监督的运动疗法 (SET) 可减轻症状并改善步行能力，并在共识指南中推荐。¹从历史上看，缺乏对 SET 的补偿极大地限制了访问和利用。²然而，2017 年 5 月，医疗保险和医疗补助服务中心 (CMS) 确定证据足以涵盖间歇性跛行受益人的 SET。尽管这为创建新的 SET 计划和扩展现有计划提供了报酬，但自 CMS 的报销决定以来，关于 SET 的使用和结果的数据很少。本研究旨在通过利用医疗保险受益人数据来解决这种数据缺乏问题。

支持本研究结果的数据可根据合理要求从通讯作者处获得。该研究得到了贝斯以色列女执事医疗中心机构审查委员会的批准。具有 SET 或国际疾病分类、第十次修订临床修改的当前程序术语代码的患者CMS 2017年6月1日（对应CMS的报销协议）至2018年12月31日期间SET报销要求的间歇性跛行代码，包含在100% CMS机构门诊文件中。基线特征和合并症是通过 MedPAR、载体和慢性病仓库文件中的 1 年回顾获得的。结果包括截至 2018 年 12 月 31 日的全因死亡、下肢血运重建以及因心肌梗塞、充血性心力衰竭或中风住院。

患者被划分为存在或不存在 SET 当前程序术语代码。分类变量报告为频率和比例并用χ相比²或Fisher精确检验，根据。为了说明患者之间的基线差异，使用所有基线特征为每位患者计算接受 SET 的倾向评分。然后使用倾向评分将每个 SET 患者与三个最近的未暴露患者进行匹配。然后使用 Cox 回归来评估匹配人群中 SET 和结果之间的关联。使用细灰色方法来解释非死亡结果的死亡竞争风险。所有P <0.05 被认为是显着的。

在诊断为间歇性跛行的 129699 名患者中，1735 名 (1.3%) 在研究期间被纳入 SET。参加 SET 会议的中位数为 16（四分位距，6-28），89 名患者（5.1%）完成了该计划（36 次会议）。与未入组的患者 (n=127 964) 相比，SET 患者年龄稍大（73.6±8.0 岁与 73.1±9.1 岁），更有可能是白人（87.2% 对 84.0%），黑人的可能性更小（8.8 % 对 10.9%）、双重参加医疗补助（12.7% 对 22.4%）和女性（39.0% 对 42.5%）（表）。大多数参加 SET 的患者来自美国中西部 (48.1%) 和东北部 (16.1%) 地区。只有 9.2% 和 12.6% 的 SET 患者分别来自美国南大西洋和南部地区。相比下，

桌子。通过 SET 转诊分层的患者特征和结果

所有 SET 与非 SET 患者的特征和 1 年累积发病率以及倾向评分匹配的队列。SET 表示有监督的运动疗法。

SET 患者的中位随访时间为 153 天（四分位距，77-252 天），非 SET 患者的随访中位时间为 244 天（四分位距，130-362 天）。参与 SET 的患者血管内和手术血运重建的 1 年累积发生率分别为 11.9% 和 2.4%（表）。在随访期间，没有接受 SET 的患者截肢。在匹配队列分析（n = 6940 名患者）中，接受 SET 的患者血管内或手术血运重建的使用率显着降低（血管内：风险比，0.49 [95% CI，0.40–0.60]，P <0.001；手术：风险比，0.27 [95% CI，0.18–0.42]，P <0.001）。组间结果没有其他差异（表）。

在这项针对有症状的外周动脉疾病的医疗保险受益人的研究中，我们发现尽管获得了 IA 类指南的认可，但在 CMS 批准后的前 19 个月内，SET 的利用率非常低。¹事实上，转诊率与 PORTRAIT（与外周动脉疾病治疗实践相关的以患者为中心的结果：调查轨迹）登记处的数据相似，该登记处在报销批准之前。³转诊到 SET 的患者与未登记的患者相比，在种族、性别、社会经济地位和地理区域方面存在差异，这表明在实施早期就出现了差异。入组后对 SET 的参与是有限的，很少有患者完成完整的计划。

这些数据凸显了在美国增加 SET 注册以及提高注册后的依从性需要付出更大的努力。实现这一目标的策略可能包括加大力度向提供者和患者宣传 SET 的好处，投资扩大 SET 项目的区域可用性和总数，以及考虑 SET 的新扩展（例如通过远程康复）。总体而言，需要采用多方面的方法来大幅提高利用率。此外，需要重点确保所有外周动脉疾病患者，无论种族、地理区域或社会经济地位如何，都能获得指南推荐的治疗。

本研究的局限性包括转诊到 SET 的患者数量少、事件发生率低和随访时间短、治疗选择偏倚和残留混杂的可能性、由于使用索赔代码而无法评估症状的严重程度，以及缺乏关于 SET 协议的细节。

这项工作由史密斯心脏病学结果研究中心资助。Divakaran 博士得到了哈佛催化剂和波士顿 Claude D. Pepper 老年美国人独立中心 (5P30AG031679-10) 联合 KL2/催化剂医学研究调查员培训 (CMeRIT) 奖的支持。Secemsky 博士得到了美国国立卫生研究院 (NIH)/国家心肺血液研究所 (NHLBI) K23 HL150290 和哈佛医学院海岸教师发展奖的支持。

披露无。

有关资金来源和披露信息，请参见第 916 页。