Importance Endovascular therapy (EVT) improves functional outcomes in acute ischemic stroke (AIS) with large vessel occlusion (LVO). Whether implementation of a regional prehospital transport policy for comprehensive stroke center triage increases use of EVT is uncertain. Objective To evaluate the association of a regional prehospital transport policy that directly triages patients with suspected LVO stroke to the nearest comprehensive stroke center with rates of EVT. Design, Setting, and Participants This retrospective, multicenter preimplementation-postimplementation study used an interrupted time series analysis to compare treatment rates before and after implementation in patients with AIS arriving at 15 primary stroke centers and 8 comprehensive stroke centers in Chicago, Illinois, via emergency medical services (EMS) transport from December 1, 2017, to May 31, 2019 (9 months before and after implementation in September 2018). Data were analyzed from December 1, 2017, to May 31, 2019. Interventions Prehospital EMS transport policy to triage patients with suspected LVO stroke, using a 3-item stroke scale, to comprehensive stroke centers. Main Outcomes and Measures Rates of EVT before and after implementation among EMS-transported patients within 6 hours of AIS onset. Results Among 7709 patients with stroke, 663 (mean [SD] age, 68.5 [14.9] years; 342 women [51.6%] and 321 men [48.4%]; and 348 Black individuals [52.5%]) with AIS arrived within 6 hours of stroke onset by EMS transport: 310 of 2603 (11.9%) in the preimplementation period and 353 of 2637 (13.4%) in the postimplementation period. The EVT rate increased overall among all patients with AIS (preimplementation, 4.9% [95% CI, 4.1%-5.8%]; postimplementation, 7.4% [95% CI, 7.5%-8.5%]; P < .001) and among EMS-transported patients with AIS within 6 hours of onset (preimplementation, 4.8% [95% CI, 3.0%-7.8%]; postimplementation, 13.6% [95% CI, 10.4%-17.6%]; P < .001). On interrupted time series analysis among EMS-transported patients, the level change within 1 month of implementation was 7.15% (P = .04) with no slope change before (0.16%; P = .71) or after (0.08%; P = .89), which indicates a step rather than gradual change. No change in time to thrombolysis or rate of thrombolysis was observed (step change, 1.42%; P = .82). There were no differences in EVT rates in patients not arriving by EMS in the 6- to 24-hour window or by interhospital transfer or walk-in, irrespective of time window. Conclusions and Relevance Implementation of a prehospital transport policy for comprehensive stroke center triage in Chicago was associated with a significant, rapid, and sustained increase in EVT rate for patients with AIS without deleterious associations with thrombolysis rates or times.

中文翻译：

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疑似大血管闭塞中风患者的院前综合卒中中心与原发性卒中中心分流。

重要性 血管内治疗 (EVT) 可改善大血管闭塞 (LVO) 急性缺血性卒中 (AIS) 的功能结果。实施区域性院前转运政策以进行全面的卒中中心分诊是否会增加 EVT 的使用尚不确定。目的 评估区域性院前转运政策与 EVT 发生率的关联，该政策直接将疑似 LVO 卒中患者分流到最近的综合卒中中心。设计、设置和参与者这项回顾性、多中心实施前-实施后研究使用间断时间序列分析比较到达伊利诺伊州芝加哥市 15 个初级卒中中心和 8 个综合卒中中心的 AIS 患者实施前后的治疗率，2017 年 12 月 1 日至 2019 年 5 月 31 日（2018 年 9 月实施前后 9 个月）通过紧急医疗服务 (EMS) 运输。数据分析时间为 2017 年 12 月 1 日至 2019 年 5 月 31 日。干预措施 院前 EMS 运输政策使用 3 项卒中量表将疑似 LVO 卒中患者分流至综合卒中中心。主要结果和措施 AIS 发病 6 小时内 EMS 转运患者实施前后 EVT 发生率。结果 在 7709 名卒中患者中，663 名（平均 [SD] 年龄，68.5 [14.9] 岁；342 名女性 [51.6%] 和 321 名男性 [48.4%]；以及 348 名黑人 [52.5%]）患有 AIS 的患者在 6 小时内到达EMS 运输引起的卒中发病率：实施前 2603 人中有 310 人（11.9%），实施后 2637 人中有 353 人（13.4%）。所有 AIS 患者的 EVT 率总体增加（实施前，4.9% [95% CI，4.1%-5.8%]；实施后，7.4% [95% CI，7.5%-8.5%]；P < .001）和在发病 6 小时内经 EMS 转运的 AIS 患者（实施前，4.8% [95% CI，3.0%-7.8%]；实施后，13.6% [95% CI，10.4%-17.6%]；P < .001）。在 EMS 转运患者的中断时间序列分析中，实施 1 个月内的水平变化为 7.15% (P = .04)，之前 (0.16%; P = .71) 或之后 (0.08%; P = .89)，这表明一个步骤而不是渐进的变化。未观察到溶栓时间或溶栓率的变化（阶跃变化，1.42%；P = .82）。未在 6 至 24 小时窗口内通过 EMS 到达或通过医院间转运或步入式到达的患者的 EVT 率没有差异，与时间窗口无关。结论和相关性 在芝加哥实施综合卒中中心分诊的院前转运政策与 AIS 患者的 EVT 率显着、快速和持续增加相关，而与溶栓率或溶栓时间没有有害关联。