Probst Pascal, Grummich Kathrin, Heger Patrick, Zaschke Steffen, Knebel Phillip, Ulrich Alexis, Büchler Markus W, Diener Markus K
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.
Syst Rev. 2016 Mar 24;5:48. doi: 10.1186/s13643-016-0226-4.
Blinding is a measure in randomized controlled trials (RCT) to reduce detection and performance bias. There is evidence that lack of blinding leads to overestimated treatment effects. Because of the physical component of interventions, blinding is not easily applicable in surgical trials. This is a protocol for a systematic review and empirical study about actual impact on outcomes and future potential of blinding in general and abdominal surgery RCT.
METHODS/DESIGN: A systematic literature search in CENTRAL, MEDLINE and Web of Science will be conducted to locate RCT between 1996 and 2015 with a surgical intervention. General study characteristics and information on blinding methods will be extracted. The risk of performance and detection bias will be rated as low, unclear or high according to the Cochrane Collaboration's tool for assessing risk of bias. The main outcome of interest will be the association of a high risk of performance or detection bias with significant trial results and will be tested at a level of significance of 5 %. Further, trials will be meta-analysed in a Mantel-Haenszel model comparing trials with high risk of bias to other trials at a level of significance of 5 %.
Detection and performance bias distort treatment effects. The degree of such bias in general and abdominal surgery is unknown. Evidence on influence of missing blinding would improve critical appraisal and conduct of general and abdominal surgery RCT.
PROSPERO 2015: CRD42015026837.
设盲是随机对照试验（RCT）中用于减少检测和实施偏倚的一种措施。有证据表明，缺乏设盲会导致治疗效果被高估。由于干预措施具有物理性组成部分，设盲在外科试验中不易实施。这是一项关于设盲在普通外科和腹部外科RCT中对结果的实际影响及未来潜力的系统评价和实证研究方案。
方法/设计：将在Cochrane系统评价数据库（CENTRAL）、医学期刊数据库（MEDLINE）和科学引文索引数据库（Web of Science）中进行系统文献检索，以查找1996年至2015年间采用外科干预的RCT。将提取一般研究特征和设盲方法的信息。根据Cochrane协作网评估偏倚风险的工具，将实施偏倚和检测偏倚的风险评为低、不清楚或高。主要关注的结果将是实施或检测偏倚高风险与显著的试验结果之间的关联，并将在5%的显著性水平上进行检验。此外，将采用Mantel-Haenszel模型对试验进行Meta分析，在5%的显著性水平上比较偏倚风险高的试验与其他试验。
检测和实施偏倚会扭曲治疗效果。普通外科和腹部外科中此类偏倚的程度尚不清楚。关于缺乏设盲影响的证据将改善对普通外科和腹部外科RCT的批判性评价和实施。
国际前瞻性系统评价注册库（PROSPERO）2015年注册号：CRD42015026837。
