Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
The Study Center of the German Surgical Society (SDGC), University of Heidelberg, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany.
Langenbecks Arch Surg. 2019 May;404(3):273-284. doi: 10.1007/s00423-019-01761-6. Epub 2019 Mar 1.
Blinding reduces performance and detection bias in randomized controlled trials (RCT). There is evidence that lack of blinding leads to overestimation of treatment effects in pharmacological trials. Since surgical trials use interventions with a physical component, blinding is often complicated. The aim of this study was to analyze, in general and abdominal surgery RCT, the status of blinding, the potential for blinding, and the influence of blinding on outcomes.
A systematic search of the literature in CENTRAL, MEDLINE, and Web of Science was conducted to identify RCT with a surgical intervention, starting in 1996, the year when the first CONSORT statement was published. Information on general study characteristics and blinding methods was extracted. The presence or absence of blinding of the study contributors-patients, surgeons, data collectors, outcome assessors, and data analysts-was analyzed. The association of blinding with the trial outcome was investigated for every study contributor.
Out of 29,119 articles, 378 RCT were included in the analysis. These investigated a total of 62,522 patients, of whom 15,025 were blinded (24.0%). Contributors could have been blinded in far more trials, as the potential for blinding measures ranged from 69% for outcome assessors to 98% for data analysts. If blinding of surgeons would have been possible but had not been performed, this was associated with more significant trial outcomes (OR 13.670; 95% CI 1.308 to 142.840; p = 0.0289).
The potential of blinding, an important quality measure in surgical RCT, has not been exhausted. This study summarizes the existing evidence on blinding in surgical trials and gives evidence-based recommendations for the use of blinding in future surgical trials.
PROSPERO 2015:CRD42015026837.
盲法可降低随机对照试验（RCT）中的偏倚和结果评估偏倚。有证据表明，缺乏盲法会导致药理学试验中治疗效果的高估。由于外科试验采用具有物理成分的干预措施，盲法通常很复杂。本研究旨在分析一般外科和腹部外科 RCT 中盲法的现状、潜在可能性以及盲法对结局的影响。
系统检索 CENTRAL、MEDLINE 和 Web of Science 中的文献，以确定 1996 年首次发表 CONSORT 声明后开始的外科干预 RCT。提取一般研究特征和盲法方法信息。分析研究参与者（患者、外科医生、数据收集者、结局评估者和数据分析者）的盲法状态。调查每个研究参与者的盲法与试验结局的关系。
在 29119 篇文章中，有 378 项 RCT 纳入分析。这些试验共纳入 62522 例患者，其中 15025 例患者被盲法（24.0%）。如果潜在可能性得以实现，更多的试验参与者可以被盲法，因为潜在可能性的衡量范围从结局评估者的 69%到数据分析者的 98%。如果可能对外科医生进行盲法但未执行，则与更显著的试验结局相关（OR 13.670；95%CI 1.308 至 142.840；p=0.0289）。
盲法的可能性，外科 RCT 的一个重要质量指标，尚未得到充分利用。本研究总结了外科试验中盲法的现有证据，并为未来外科试验中盲法的使用提供了循证建议。
PROSPERO 2015：CRD42015026837。
