Department of Healthcare Epidemiology, Kyoto University Graduate School of Medicine, Kyoto, Japan; Department of Nephrology and Dialysis, Kyoritsu Hospital, Hyogo, Japan.
The Australian and New Zealand Intensive Care Research Centre, the School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
J Clin Epidemiol. 2020 Feb;118:107-114.e5. doi: 10.1016/j.jclinepi.2019.10.004. Epub 2019 Oct 22.
The objective of the study was to assess trial-level factors associated with the contribution of individual participant data (IPD) to IPD meta-analyses, and to quantify the data availability bias, namely the difference between the effect estimates of trials contributing IPD and those not contributing IPD in the same systematic reviews (SRs).
We included SRs of randomized controlled trials (RCTs) with IPD meta-analyses since 2011. We extracted trial-level characteristics and examined their association with IPD contribution. To assess the data availability bias, we retrieved odds ratios from the original RCT articles, calculated the ratio of odds ratios (RORs) between aggregate data (AD) meta-analyses of RCTs contributing IPD and those of RCTs not contributing IPD for each SR, and meta-analytically synthesized RORs.
Of 728 eligible RCTs included in 31 SRs, 321 (44%) contributed IPD, whereas 407 (56%) did not. A recent publication year, larger number of participants, adequate allocation concealment, and impact factor ≥10 were associated with IPD contribution. We found the SRs yielded widely different estimates of RORs. Overall, there was no significant difference in the pooled effect estimates of AD meta-analyses between RCTs contributing and not contributing IPD (ROR 1.01, 95% confidence interval, 0.86-1.19).
There was no consistent evidence of a data availability bias in recent IPD meta-analyses of RCTs with dichotomous outcomes. Higher methodological qualities of trials were associated with IPD contribution.
本研究旨在评估与个体参与者数据（IPD）对 IPD 荟萃分析的贡献相关的试验水平因素，并量化数据可得性偏差，即具有 IPD 的试验与同一系统评价（SR）中未提供 IPD 的试验的效应估计值之间的差异。
我们纳入了自 2011 年以来具有 IPD 荟萃分析的随机对照试验（RCT）的 SR。我们提取了试验水平特征，并检查了它们与 IPD 贡献的关系。为了评估数据可得性偏差，我们从原始 RCT 文章中检索了比值比（ORs），计算了具有 IPD 的 RCT 的汇总数据（AD）荟萃分析与不具有 IPD 的 RCT 的 AD 荟萃分析之间的 OR 比值（ROR），并对 ROR 进行了荟萃分析。
在 31 项 SR 中，纳入了 728 项符合条件的 RCT，其中 321 项（44%）提供了 IPD，而 407 项（56%）未提供。最近的出版年份、更多的参与者、充分的分配隐藏和影响因子≥10 与 IPD 贡献有关。我们发现，SR 得出的 ROR 估计值差异很大。总体而言，具有 IPD 的 RCT 和不具有 IPD 的 RCT 的 AD 荟萃分析的合并效应估计值没有显著差异（ROR 1.01，95%置信区间，0.86-1.19）。
在最近具有二分类结局的 RCT 的 IPD 荟萃分析中，没有一致的证据表明存在数据可得性偏差。试验的方法学质量较高与 IPD 贡献有关。
