LeBrun Drake G, Bido Jen, Kocher Mininder S, Baldwin Keith D, Fabricant Peter D
Department of Orthopedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY USA.
Boston Children's Hospital, Boston, MA USA.
HSS J. 2020 Dec;16(Suppl 2):366-371. doi: 10.1007/s11420-020-09753-9. Epub 2020 Mar 30.
Observational studies constitute the majority of the orthopedic literature, each type distinct in terms of what it can and cannot measure. Case-control studies select participants based on outcome status, not exposure status, and therefore differ from other observational studies in their aims, limitations, and conclusions. Misclassification of a different kind of study as a case-control study can lead to misinterpretation of the data and misreporting of its level of evidence (LOE), either "overselling" or "underselling" its importance.
QUESTIONS/PURPOSES: We sought to answer three questions: (1) How frequently do studies reported to be orthopedic case-control studies actually reflect other study designs? (2) What factors might be associated with misclassification? (3) How does study design misclassification affect LOE reporting?
A bibliometric analysis was performed to identify all studies published in 75 orthopedic journals over a one-year period (January 2017 through December 2017) that included the term "case-control" in the title, abstract, or main text. We identified the proportion of studies that were misclassified as "case-control" in design and recorded the associated changes in reported LOE. We also examined associations between study misclassification (and by extension LOE misclassification) and the study specialty, journal specialty, and journal impact factor.
Of 339 studies that reported a case-control design, 227 (67%) were misclassified and reflected other study designs. The study designs most often misclassified as case-control designs were retrospective cohort studies ( = 97; 43%) and cross-sectional studies ( = 88; 39%). The frequency of misclassification was associated with the subspecialty of the journal and the impact factor but not the study subspecialty. After correction of the LOE in the misclassified studies that reported an LOE ( = 193), it was found that 28 (15%) had underreported their LOE, and eight (4%) had overreported their LOE.
Studies reported in the orthopedic literature to have a case-control design frequently have another study design, and this pattern is consistent across subspecialties. Enhanced rigor in accurately defining study designs in orthopedics could be achieved through training and stricter review processes.
观察性研究构成了骨科文献的大部分，每种类型在所能测量和不能测量的方面都有所不同。病例对照研究根据结果状态而非暴露状态选择参与者，因此在目的、局限性和结论方面与其他观察性研究不同。将一种不同类型的研究错误分类为病例对照研究可能导致数据的错误解读及其证据水平（LOE）的错误报告，要么“夸大”要么“低估”其重要性。
问题/目的：我们试图回答三个问题：（1）报告为骨科病例对照研究的研究实际上反映其他研究设计的频率有多高？（2）哪些因素可能与错误分类有关？（3）研究设计错误分类如何影响LOE报告？
进行文献计量分析，以识别在一年期间（2017年1月至2017年12月）在75种骨科期刊上发表的所有标题、摘要或正文包含“病例对照”一词的研究。我们确定了设计上被错误分类为“病例对照”的研究比例，并记录了报告的LOE的相关变化。我们还研究了研究错误分类（以及由此延伸的LOE错误分类）与研究专业、期刊专业和期刊影响因子之间的关联。
在报告病例对照设计的339项研究中，227项（67%）被错误分类并反映了其他研究设计。最常被错误分类为病例对照设计的研究设计是回顾性队列研究（n = 97；43%）和横断面研究（n = 88；39%）。错误分类的频率与期刊的亚专业和影响因子有关，但与研究亚专业无关。在对报告了LOE的错误分类研究（n = 193）的LOE进行校正后，发现28项（15%）低估了其LOE，8项（4%）高估了其LOE。
骨科文献中报告为病例对照设计的研究经常采用其他研究设计，并且这种模式在各亚专业中是一致的。通过培训和更严格的审查过程，可以提高骨科研究设计准确定义的严谨性。
