February 13, 2018
Abstract
Importance 背景
The safety of the pulmonary embolism rule-out criteria (PERC), an 8-item block of clinical criteria aimed at ruling out pulmonary embolism (PE), has not been assessed in a randomized clinical trial.
PE排除标准(PERC)包括8项临床标准，旨在排除PE。其安全性尚未经过随机临床试验证实。
Objective 目的
To prospectively validate the safety of a PERC-based strategy to rule out PE.
前瞻性验证基于PERC排除PE策略的安全性
Design, Setting, and Patients 设计、场景和研究人群
A crossover cluster–randomized clinical noninferiority trial in 14 emergency departments in France. Patients with a low gestalt clinical probability of PE were included from August 2015 to September 2016, and followed up until December 2016.
在法国14个急诊科进行的一项交叉群组随机临床非劣效试验。纳入2015年8月至2016年9月间PE临床概率较低的患者，并随访至2016年12月。
Interventions 干预措施
Each center was randomized for the sequence of intervention periods. In the PERC period, the diagnosis of PE was excluded with no further testing if all 8 items of the PERC rule were negative.
随机分配每个中心实施干预措施的次序。在PERC阶段，如果PERC标准中所有8项指标均为阴性，无需经过任何进一步检查即可排除PE诊断。
Main Outcomes and Measures 主要预后指标
The primary end point was the occurrence of a thromboembolic event during the 3-month follow-up period that was not initially diagnosed. The noninferiority margin was set at 1.5%. Secondary end points included the rate of computed tomographic pulmonary angiography (CTPA), median length of stay in the emergency department, and rate of hospital admission.
主要预后终点为最初未诊断PE的患者在3个月随访期间发生血栓栓塞事件。非劣效界值设置为1.5%。次要终点包括CTPA比例、急诊科中位住院时间及住院率。
Results 结果
Among 1916 patients who were cluster-randomized (mean age 44 years, 980 [51%] women), 962 were assigned to the PERC group and 954 were assigned to the control group. A total of 1749 patients completed the trial. A PE was diagnosed at initial presentation in 26 patients in the control group (2.7%) vs 14 (1.5%) in the PERC group (difference, 1.3% [95% CI, −0.1% to 2.7%]; P = .052). One PE (0.1%) was diagnosed during follow-up in the PERC group vs none in the control group (difference, 0.1% [95% CI, −∞ to 0.8%]). The proportion of patients undergoing CTPA in the PERC group vs control group was 13% vs 23% (difference, −10% [95% CI, −13% to −6%]; P < .001). In the PERC group, rates were significantly reduced for the median length of emergency department stay (mean reduction, 36 minutes [95% CI, 4 to 68]) and hospital admission (difference, 3.3% [95% CI, 0.1% to 6.6%]).
在接受群组随机的1916名患者中（平均年龄44岁，980名[51%]为女性），962名被分至PERC组，954名被分至对照组。共有1749名患者完成试验。就诊时对照组26名患者(2.7%)及PERC组14名患者(1.4%)被诊断为PE（差异，1.3% [95% CI, −0.1% to 2.7%]; P = .052）。PERC组随访期间1名患者(0.1%)诊断为PE，对照组没有（差异，0.1% [95% CI, −∞ to 0.8%]）。PERC组与对照组进行CTPA检查的患者比例为13% vs. 23%（差异，−10% [95% CI, −13% to −6%]; P < .001）。PERC组患者急诊科住院时间显著缩短（平均减少36分钟 [95% CI, 4 to 68]），住院率显著降低（差异，3.3% [95% CI, 0.1% to 6.6%]）。
Conclusions and Relevance 结论及意义
Among very low-risk patients with suspected PE, randomization to a PERC strategy vs conventional strategy did not result in an inferior rate of thromboembolic events over 3 months. These findings support the safety of PERC for very low-risk patients presenting to the emergency department.
对于非常低危的疑似PE患者，与传统治疗策略相比，随机分配至PERC策略组并未导致3个月期间血栓栓塞事件发生率降低。这些发现支持在急诊科就诊的极低危患者使用PERC的安全性。
Trial Registration 试验注册
clinicaltrials.gov Identifier: NCT02375919
