Esene Ignatius N, Ngu Julius, El Zoghby Mohamed, Solaroglu Ihsan, Sikod Anna M, Kotb Ali, Dechambenoit Gilbert, El Husseiny Hossam
Department of Neurosurgery, Ain Shams University, Cairo, Egypt,
Childs Nerv Syst. 2014 Aug;30(8):1321-32. doi: 10.1007/s00381-014-2460-1.
Case series (CS) are well-known designs in contemporary use in neurosurgery but are sometimes used in contexts that are incompatible with their true meaning as defined by epidemiologists. This inconsistent, inappropriate and incorrect use, and mislabeling impairs the appropriate indexing and sorting of evidence.
Using PubMed, we systematically identified published articles that had "case series" in the "title" in 15 top-ranked neurosurgical journals from January 2008 to December 2012. The abstracts and/or full articles were scanned to identify those with descriptions of the principal method as being "case series" and then classified as "true case series" or "non-case series" by two independent investigators with 100 % inter-rater agreement.
Sixty-four articles had the label "case series" in their "titles." Based on the definition of "case series" and our appraisal of the articles using Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines, 18 articles (28.13 %) were true case series, while 46 (71.87 %) were mislabeled. Thirty-five articles (54.69 %) mistook retrospective (descriptive) cohorts for CS. CS are descriptive with an outcome-based sampling, while "descriptive cohorts" have an exposure-based sampling of patients, followed over time to assess outcome(s). A comparison group is not a defining feature of a cohort study and distinguishes descriptive from analytic cohorts.
A distinction between a case report, case series, and descriptive cohorts is absolutely necessary to enable the appropriate indexing, sorting, and application of evidence. Researchers need better training in methods and terminology, and editors and reviewers should scrutinize more carefully manuscripts claiming to be "case series" studies.
病例系列（CS）是当代神经外科常用的设计，但有时在与流行病学家所定义的真实含义不相符的情况下使用。这种不一致、不恰当和不正确的使用以及错误标注会损害证据的适当索引和分类。
利用PubMed，我们系统地检索了2008年1月至2012年12月期间在15种顶级神经外科期刊上发表的标题中含有“病例系列”的文章。扫描摘要和/或全文，以识别那些将主要方法描述为“病例系列”的文章，然后由两名独立研究人员将其分类为“真正的病例系列”或“非病例系列”，评分者间一致性为100%。
64篇文章的标题中有“病例系列”的标签。根据“病例系列”的定义以及我们使用《加强流行病学观察性研究报告规范》（STROBE）指南对文章的评估，18篇文章（28.13%）是真正的病例系列，而46篇（71.87%）被错误标注。35篇文章（54.69%）将回顾性（描述性）队列误认为病例系列。病例系列是基于结果的抽样描述性研究，而“描述性队列”是基于暴露的患者抽样，随访一段时间以评估结果。对照组不是队列研究的定义特征，它区分了描述性队列和分析性队列。
区分病例报告、病例系列和描述性队列对于实现证据的适当索引、分类和应用绝对必要。研究人员需要在方法和术语方面接受更好的培训，编辑和审稿人应该更仔细地审查声称是“病例系列”研究的手稿。
