ST5 Vascular Surgery, Leicester Royal Infirmary, Leicester, LE1 5WW, UK.
ST3 General Surgery, University Hospitals Coventry and Warwickshire NHS Trust, Infirmary square, UK.
J Clin Epidemiol. 2014 Aug;67(8):897-903. doi: 10.1016/j.jclinepi.2014.03.003. Epub 2014 Apr 29.
To assess the utility of funnel plots in assessing publication bias (PB) in meta-analyses of proportion studies.
Meta-analysis simulation study and meta-analysis of published literature reporting peri-operative mortality after abdominal aortic aneurysm (AAA) repair. Data for the simulation study were stochastically generated. A literature search of Medline and Embase was performed to identify studies for inclusion in the published literature meta-analyses.
The simulation study demonstrated that conventionally constructed funnel plots (log odds vs. 1/standard error [1/SE]) for extreme proportional outcomes were asymmetric despite no PB. Alternative funnel plots constructed using study size rather than 1/SE showed no asymmetry for extreme proportional outcomes. When used in meta-analyses of the mortality of AAA repair, these alternative funnel plots highlighted the possibility for conventional funnel plots to demonstrate asymmetry when there was no evidence of PB.
Conventional funnel plots used to assess for potential PB in meta-analyses are inaccurate for meta-analyses of proportion studies with low proportion outcomes. Funnel plots of study size against log odds may be a more accurate way of assessing for PB in these studies.
评估漏斗图在评估腹部主动脉瘤（AAA）修复术后围手术期死亡率的比例研究荟萃分析中的发表偏倚（PB）的效用。
荟萃分析模拟研究和发表文献的荟萃分析，报告 AAA 修复术后围手术期死亡率。模拟研究的数据是随机生成的。对 Medline 和 Embase 进行文献检索，以确定纳入发表文献荟萃分析的研究。
模拟研究表明，尽管没有 PB，但传统构建的用于极端比例结果的漏斗图（log 优势比与 1/标准误差[1/SE]）不对称。使用研究大小而不是 1/SE 构建的替代漏斗图显示，对于极端比例结果，没有不对称性。当用于 AAA 修复死亡率的荟萃分析时，这些替代漏斗图突出了在没有 PB 证据的情况下，传统漏斗图可能显示不对称性的可能性。
用于评估荟萃分析中潜在 PB 的传统漏斗图对于低比例结果的比例研究荟萃分析不准确。研究大小与 log 优势比的漏斗图可能是评估这些研究中 PB 的更准确方法。
