Division of Critical Care, Department of Medicine, Western University, 1151 Richmond Street London, Ontario, N6A 3K7, Canada.
Faculty of Health Sciences, McMaster University, 1280 Main St. West, Hamilton, Ontario, L8S 4L8, Canada.
J Clin Epidemiol. 2021 Nov;139:68-79. doi: 10.1016/j.jclinepi.2021.07.002. Epub 2021 Jul 15.
To describe the characteristics of Covid-19 randomized clinical trials (RCTs) and examine the association between trial characteristics and the likelihood of finding a significant effect.
We conducted a systematic review to identify RCTs (up to October 21, 2020) evaluating drugs or blood products to treat or prevent Covid-19. We extracted trial characteristics (number of centers, funding sources, and sample size) and assessed risk of bias (RoB) using the Cochrane RoB 2.0 tool. We performed logistic regressions to evaluate the association between RoB due to randomization, single vs. multicentre, funding source, and sample size, and finding a statistically significant effect.
We included 91 RCTs (n = 46,802); 40 (44%) were single-center, 23 (25.3%) enrolled <50 patients, 28 (30.8%) received industry funding, and 75 (82.4%) had high or probably high RoB. Thirty-eight trials (41.8%) reported a statistically significant effect. RoB due to randomization and being a single-center trial were associated with increased odds of finding a statistically significant effect.
There is high variability in RoB among Covid-19 trials. Researchers, funders, and knowledge-users should be cognizant of the impact of RoB due to randomization and single-center trial status in designing, evaluating, and interpreting the results of RCTs.
CRD42020192095.
描述 COVID-19 随机临床试验（RCT）的特征，并研究试验特征与发现显著效果的可能性之间的关系。
我们进行了系统综述，以确定评估药物或血液制品治疗或预防 COVID-19 的 RCT（截至 2020 年 10 月 21 日）。我们提取了试验特征（中心数量、资金来源和样本量），并使用 Cochrane RoB 2.0 工具评估了偏倚风险（RoB）。我们进行了逻辑回归，以评估随机分组、单中心与多中心、资金来源和样本量与发现统计学显著效果之间的关系。
我们纳入了 91 项 RCT（n=46802）；40 项（44%）为单中心，23 项（25.3%）纳入的患者<50 例，28 项（30.8%）获得了产业资金，75 项（82.4%）的 RoB 为高或极可能高。38 项试验（41.8%）报告了统计学显著效果。随机分组和单中心试验的 RoB 与发现统计学显著效果的可能性增加相关。
COVID-19 试验的 RoB 存在高度变异性。研究人员、资助者和知识使用者在设计、评估和解释 RCT 的结果时，应意识到随机分组和单中心试验状态的 RoB 的影响。
CRD42020192095。
