Minimally Invasive Surgery Research Center, Iran University of Medical Sciences, Tehran, Iran.
Cochrane Iran Associate Centre, National Institute for Medical Research Development (NIMAD), Tehran, Iran.
Arch Iran Med. 2022 Jun 1;25(6):375-382. doi: 10.34172/aim.2022.61.
Among interventional studies, randomized controlled trials (RCTs) provide the highest level of evidence. However, RCTs can be susceptible to the risk of bias (RoB). Systematic reviews can be performed to appraise RoB in the included articles using evaluative tools. This study aimed to describe the main characteristics and focus on the RoB of RCTs conducted in Iran and included in Cochrane Reviews (CRs).
We searched "Iran" by selecting the "Search All Text" and "Review" fields in the within Ovid. CRs that included the RCTs conducted in Iran were retrieved. A trial was selected only if it was included in CRs, described as a controlled clinical trial, involved human subjects and CR authors assessed its RoB. The trials were characterized by investigating the relevant articles and the table "Characteristics of included studies" in each CR. The RoB was investigated by collecting the review authors' judgments based on RoB assessment tables in the CRs.
Out of 1166 Iranian RCTs included by 571 CRs, low RoB was found in 44.9% for random sequence generation, 20.8% for allocation concealment, 32.3% for blinding of participants/personnel, 36.5% for blinding of outcome assessors, 56.3% for incomplete outcome data, 41.3% for selective outcome reporting and 53.8% for other sources of bias.
The RoB in Iranian RCTs was found to be mostly high or unclear. While this is similar to the global situation, it is recommended that the methodological quality of conducting and reporting RCTs be addressed in Iran.
在介入性研究中，随机对照试验（RCT）提供了最高级别的证据。然而，RCT 可能容易受到偏倚风险（RoB）的影响。系统评价可以使用评估工具对纳入文章中的 RoB 进行评估。本研究旨在描述在伊朗进行并纳入 Cochrane 评价（CR）的 RCT 的主要特征，并重点关注其 RoB。
我们通过在 Ovid 中的“Search All Text”和“Review”字段中选择“伊朗”进行搜索，检索到包含伊朗 RCT 的 CR。只有当试验被纳入 CR 中，被描述为对照临床试验，涉及人类受试者且 CR 作者评估其 RoB 时，才会选择该试验。通过调查相关文章和每个 CR 中的“纳入研究特征”表来描述试验。通过收集 CR 中 RoB 评估表中审查作者的判断来调查 RoB。
在 571 项 CR 中纳入的 1166 项伊朗 RCT 中，随机序列生成的 RoB 为 44.9%，分配隐藏的 RoB 为 20.8%，参与者/人员盲法的 RoB 为 32.3%，结果评估者盲法的 RoB 为 36.5%，结局数据不完整的 RoB 为 56.3%，选择性结局报告的 RoB 为 41.3%，其他偏倚来源的 RoB 为 53.8%。
伊朗 RCT 的 RoB 大多被认为是高或不明确的。虽然这与全球情况相似，但建议在伊朗解决 RCT 的实施和报告的方法学质量问题。
