The Utstein reporting template classifies the etiology of OHCA into “presumed cardiac” and “obvious non-cardiac” or “medical” and “non-medical” categories; however, the accuracy of these classifications is unclear. Ascertaining more accurately the etiology of OHCA is important to tailor advanced life support and identify etiologically consistent patient cohorts for reporting incidence and outcome and enrollment in clinical trials. This scoping review was proposed to identify the state of agreement on etiological classification based on emergency medical service (EMS) data using the Utstein format against other sources. We searched Medline, EBM-Cochrane, and Embase databases from 1946-2023 to identify studies that reported initial and confirmed etiologies of OHCA. A descriptive review of the included studies was conducted. The search yielded 22,994 citations. After excluding duplicates, 16,932 citations were reviewed for titles and abstracts. Twelve studies met the inclusion criteria of this review. The frequency of presumed cardiac etiologies based on EMS data was higher than confirmed cardiac etiologies (88% vs 33%) with 83–94% sensitivity and 73–76% specificity. In contrast, the frequency of presumed non-cardiac etiologies was lower than confirmed non-cardiac etiologies (3% vs 27%) with 52–74% sensitivity and 90–97.7% specificity estimated for respiratory disease. Major disparities exist between current etiological classifications based on the Utstein reporting template and robust sources such as autopsy and medical records. Data linkage and validation are necessary to confirm the etiology of OHCA. Further research is needed on how this misclassification affects reported incidence and outcomes, and how contributing factors may improve etiological classifications.

中文翻译：

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院外心脏骤停病因分类的准确性：范围界定审查

Utstein 报告模板将 OHCA 的病因分为“推测心脏性”和“明显非心脏性”或“医学性”和“非医学性”类别；然而，这些分类的准确性尚不清楚。更准确地确定 OHCA 的病因对于定制高级生命支持和确定病因一致的患者队列以报告发病率和结果以及临床试验的入组非常重要。提出本次范围界定审查的目的是为了根据使用 Utstein 格式的紧急医疗服务 (EMS) 数据与其他来源的数据来确定病因学分类的一致状态。我们检索了 1946 年至 2023 年的 Medline、EBM-Cochrane 和 Embase 数据库，以确定报告初步和确认 OHCA 病因的研究。对纳入的研究进行了描述性审查。搜索产生了 22,994 次引用。排除重复后，对 16,932 条引用的标题和摘要进行了审查。十二项研究符合本次综述的纳入标准。基于 EMS 数据推测的心脏病病因的频率高于已确认的心脏病病因（88% vs 33%），敏感性为 83-94%，特异性为 73-76%。相比之下，假定的非心脏病因的频率低于确诊的非心脏病因的频率（3% vs 27%），呼吸系统疾病的敏感性为 52-74%，特异性为 90-97.7%。当前基于 Utstein 报告模板的病因学分类与尸检和医疗记录等可靠来源之间存在重大差异。数据链接和验证对于确认 OHCA 的病因是必要的。需要进一步研究这种错误分类如何影响报告的发病率和结果，以及影响因素如何改善病因学分类。