Supplementary Material for: Simulated patients to demonstrate common stroke syndromes: accurate and convincing

Introduction Stroke detection in the preclinical setting is challenging, resulting in more than 1/3 of missed strokes by EMS personnel. Recently, prehospital identification of anterior large vessel occlusion (LVO) stroke has come into focus. Cortical signs have a high predictive value for the presence of LVO stroke but are often missed. Simulated patients (SPs) could be an excellent tool to train EMS personnel in the evaluation of stroke syndromes with cortical symptoms but it has not been studied whether they can simulate these important signs convincingly. The main objective of this study was thus to examine whether SPs can simulate stroke syndromes and symptoms so that stroke experts can identify them correctly and reliably, applying the NIH stroke scale (NIHSS). Methods Lay actors were trained to simulate one of 8 stroke syndromes either typical of a lacunary stroke or of an anterior LVO stroke and then videotaped during an examination according to the NIHSS. Stroke experts were asked to rate each item of the NIHSS based on the videos, determine which stroke syndrome was being demonstrated, and rate the quality of the simulation. The primary outcome was the correct identification of the target stroke syndrome by the expert raters. Secondary outcomes were the agreement of the rating of the NIHSS score with the target NIHSS score and the expert raters’ assessment of the quality of the simulation. Results Seven of eight syndromes were rated correctly by at least twelve of fifteen raters and the mean rated NIHSS score was within one point of the target score for six of eight syndromes. The mean rating for the quality of simulation was between 3.54 and 3.98 (as rated on a scale from 1 to 4) for each syndrome. Discussion/Conclusion SPs are capable of simulating acute stroke symptoms and syndromes accurately and convincingly. They thus represent a great resource to improve educational interventions that improve stroke recognition.

引言
院前环境下的脑卒中筛查颇具挑战性，导致急诊医疗服务（Emergency Medical Services, EMS）人员漏诊超过三分之一的脑卒中病例。近年来，前循环大血管闭塞（large vessel occlusion, LVO）性脑卒中的院前识别逐渐成为研究焦点。皮质体征对前循环LVO性脑卒中的存在具有较高预测价值，但常被漏诊。模拟患者（simulated patients, SPs）或可成为培训急诊医疗人员评估伴皮质症状的脑卒中综合征的优质工具，但目前尚无研究证实其能否逼真模拟此类重要体征。因此本研究的主要目的是，借助美国国立卫生研究院卒中量表（NIH Stroke Scale, NIHSS），探究模拟患者能否精准模拟脑卒中综合征与症状，使得卒中专家能够准确且可靠地识别这些表现。
方法
招募非专业演员接受培训，使其能够模拟8种脑卒中综合征中的一种——这些综合征要么为典型腔隙性脑卒中表现，要么为典型前循环LVO性脑卒中表现；随后根据NIHSS量表要求，对检查过程进行录像。邀请卒中专家基于录像对NIHSS量表的每个条目进行评分，判断所展示的脑卒中综合征类型，并对模拟质量进行评级。本研究的主要结局指标为专家评级者能否正确识别目标脑卒中综合征；次要结局指标包括NIHSS评分与目标评分的一致性，以及专家评级者对模拟质量的评估结果。
结果
8种综合征中有7种可被15名评级者中的至少12名正确识别；8种综合征中有6种的平均NIHSS评分与目标评分差值在1分以内。各综合征的模拟质量平均评级介于3.54至3.98之间（评级范围为1至4分）。
讨论/结论
模拟患者能够准确且逼真地模拟急性脑卒中症状与综合征，因此其可作为优质教学资源，用于优化提升脑卒中识别能力的教育干预方案。