Institute of Statistical Mathematics, Tachikawa, Tokyo, Japan.
Department of Biomedical Statistics, Graduate School of Medicine, and Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka, Japan.
Res Synth Methods. 2021 Sep;12(5):674-679. doi: 10.1002/jrsm.1482. Epub 2021 Feb 19.
In meta-analyses including only few studies, the estimation of the between-study heterogeneity is challenging. Furthermore, the assessment of publication bias is difficult as standard methods such as visual inspection or formal hypothesis tests in funnel plots do not provide adequate guidance. Previously, Henmi and Copas (Statistics in Medicine 2010, 29: 2969-2983) proposed a confidence interval for the overall effect in random-effects meta-analysis that is robust to publication bias to some extent. As is evident from their simulations, the confidence intervals have improved coverage compared with standard methods. To our knowledge, the properties of their method have never been assessed for meta-analyses including fewer than five studies. In this manuscript, we propose a variation of the method by Henmi and Copas employing an improved estimator of the between-study heterogeneity, in particular when dealing with few studies only. In a simulation study, the proposed method is compared to several competitors. Overall, we found that our method outperforms the others in terms of coverage probabilities.
在仅包含少数研究的荟萃分析中，估计研究间异质性具有挑战性。此外，由于标准方法（如漏斗图中的目视检查或正式假设检验）不能提供充分的指导，因此评估发表偏倚也很困难。先前，Henmi 和 Copas（《统计医学》2010 年，29：2969-2983）提出了一种针对随机效应荟萃分析总体效应的置信区间，在一定程度上对发表偏倚具有稳健性。从他们的模拟结果可以明显看出，与标准方法相比，置信区间的覆盖范围得到了改善。据我们所知，对于包含少于五项研究的荟萃分析，他们的方法的性质从未得到过评估。在本文中，我们提出了 Henmi 和 Copas 方法的一种变体，该方法采用了改进的研究间异质性估计量，特别是在仅处理少数研究时。在一项模拟研究中，将提出的方法与几种竞争对手进行了比较。总体而言，我们发现我们的方法在覆盖率方面优于其他方法。
