Clinical Trials Research Unit (CTRU), University of Leeds, 71-75 Clarendon Road, Leeds, West Yorkshire, LS2 9JT, UK.
J Clin Epidemiol. 2012 May;65(5):511-9. doi: 10.1016/j.jclinepi.2011.10.009. Epub 2012 Feb 18.
We aim to illustrate the potential impact of a new study on a meta-analysis, which gives an indication of the robustness of the meta-analysis.
A number of augmentations are proposed to one of the most widely used of graphical displays, the funnel plot. Namely, 1) statistical significance contours, which define regions of the funnel plot in which a new study would have to be located to change the statistical significance of the meta-analysis; and 2) heterogeneity contours, which show how a new study would affect the extent of heterogeneity in a given meta-analysis. Several other features are also described, and the use of multiple features simultaneously is considered.
The statistical significance contours suggest that one additional study, no matter how large, may have a very limited impact on the statistical significance of a meta-analysis. The heterogeneity contours illustrate that one outlying study can increase the level of heterogeneity dramatically.
The additional features of the funnel plot have applications including 1) informing sample size calculations for the design of future studies eligible for inclusion in the meta-analysis; and 2) informing the updating prioritization of a portfolio of meta-analyses such as those prepared by the Cochrane Collaboration.
我们旨在说明新研究对荟萃分析的潜在影响，这表明荟萃分析的稳健性。
对最广泛使用的图形显示之一——漏斗图提出了一些改进。即 1）统计显著性轮廓，定义了新研究必须位于漏斗图的哪些区域才能改变荟萃分析的统计显著性；2）异质性轮廓，显示新研究将如何影响特定荟萃分析中的异质性程度。还描述了其他一些特征，并考虑了同时使用多个特征。
统计显著性轮廓表明，无论新研究有多大，对荟萃分析的统计显著性的影响可能非常有限。异质性轮廓表明，一个离群值研究可以极大地增加异质性水平。
漏斗图的附加特征具有多种应用，包括 1）为未来有资格纳入荟萃分析的研究设计提供样本量计算的信息；2）为像 Cochrane 协作组织准备的那样的荟萃分析组合的更新优先级提供信息。
