Abdulraheem Salem, Bondemark Lars
Department of Orthodontics, Faculty of Odontology, Malmö University, Sweden.
Ministry of Health, Kuwait.
Eur J Orthod. 2019 Jan 23;41(1):54-58. doi: 10.1093/ejo/cjy021.
To analyse in 10 orthodontic journals how many randomized controlled trials (RCTs) performed 'single-', 'double-', 'triple-', or 'outcome assessors blinding' and to evaluate, from the number of RCTs that did not conduct blinding, how many could actually have achieved it.
Randomized controlled trials published in 10 orthodontic journals between 1 September 2012 and 28 February 2018 were included. A search was performed in PubMed and conducted for publication type 'randomized controlled trial' for each journal. Two reviewers independently analysed each RCT and registered that blinding was performed and included which specific type. It was also evaluated whether misclassifications of blinding items occurred and whether it was possible to achieve blinding among the RCTs that did not perform blinding.
After applying the inclusion criteria, 203 RCTs were assessed, and 61.6 per cent of them had used blinding, with the main type being 'outcome assessors blinding' (40.4%) followed by 'single-blinding' (15.3%), 'double-blinding' (2.5%), and 'triple-blinding' (3.4%). In 38.4 per cent of the trials, no blinding was performed; however, 79.4 per cent of them could have achieved blinding. Fifteen RCTs (7.3%) misclassified the blinding in relation to single-, double-, or triple-blinding. Journals followed the CONSORT (AJODO, EJO, JO, OCR) published together significantly more RCTs that performed blinding than journals not following the CONSORT.
Blinding of outcome assessors was the most frequent type, as orthodontic trials are often of intervention design and thereby difficult to mask for patients and trial staff. The misclassifications of blinding items may indicate suboptimal knowledge among researchers and peer-reviewers regarding the definitions for diverse blinding types.
分析10种正畸学杂志中有多少项随机对照试验（RCT）进行了“单盲”“双盲”“三盲”或“结果评估者盲法”，并根据未进行盲法的RCT数量评估其中实际可实现盲法的试验数量。
纳入2012年9月1日至2018年2月28日期间在10种正畸学杂志上发表的随机对照试验。在PubMed中进行检索，并针对每种杂志按“随机对照试验”的出版类型进行检索。两名评审员独立分析每项RCT，记录是否进行了盲法以及所采用的具体类型。还评估了盲法项目的错误分类情况以及未进行盲法的RCT中是否有可能实现盲法。
应用纳入标准后，评估了203项RCT，其中61.6%使用了盲法，主要类型为“结果评估者盲法”（40.4%），其次是“单盲”（15.3%）、“双盲”（2.5%）和“三盲”（3.4%）。38.4%的试验未进行盲法；然而，其中79.4%的试验本可以实现盲法。15项RCT（7.3%）在单盲、双盲或三盲方面对盲法进行了错误分类。遵循CONSORT的杂志（AJODO、EJO、JO、OCR）共同发表的进行了盲法的RCT明显多于未遵循CONSORT的杂志。
结果评估者盲法是最常见的类型，因为正畸试验通常为干预设计，因此对患者和试验人员来说难以实施遮蔽。盲法项目的错误分类可能表明研究人员和同行评审人员对不同盲法类型的定义了解不足。
