Jackson Dan
Centre for Operational Research and Applied Statistics, University of Salford, Manchester M5 4WT, UK.
Biometrics. 2007 Mar;63(1):187-93. doi: 10.1111/j.1541-0420.2006.00663.x.
Perhaps the greatest threat to the validity of a meta-analysis is the possibility of publication bias, where studies with interesting or statistically significant results are more likely to be published. This obviously impacts on inference concerning the treatment effect but also has implications for estimates of between-study variance. Two popular and established estimation methods are considered and formulae for assessing the implications of the bias are provided in terms of a general process for selecting studies. Meta-analysts, concerned that publication bias may be present, can use these as part of a sensitivity analysis to assess the robustness of their estimates of between-study variance using any selection process that is likely to be used in practice. The procedure is illustrated using a meta-analysis of clinical trials concerning the effectiveness of endoscopic sclerotherapy for preventing death in patients with cirrhosis and oesophagogastric varices.
也许对荟萃分析有效性的最大威胁是发表偏倚的可能性，即具有有趣或统计学显著结果的研究更有可能被发表。这显然会影响对治疗效果的推断，但也会对研究间方差的估计产生影响。本文考虑了两种常用且成熟的估计方法，并根据选择研究的一般过程提供了评估偏倚影响的公式。担心存在发表偏倚的荟萃分析者可以将这些作为敏感性分析的一部分，使用实际中可能采用的任何选择过程来评估其对研究间方差估计的稳健性。通过对关于内镜硬化治疗预防肝硬化和食管胃静脉曲张患者死亡有效性的临床试验进行荟萃分析来说明该程序。
