發表偏倚檢驗是元分析中最重要的一環。今天介紹的文獻是常用的檢驗方法之一：Begg和Mazumdar秩相關檢驗。這個也是CMA軟體發表偏倚輸出結果之一。大家知道怎麼解讀這個指標嗎？還不會的話，沒有關係，看看推薦的這篇經典文獻就明白了。關注微信公眾號「元分析」獲取更多精彩內容。
英文題目和摘要
Operating Characteristics of a Rank Correlation Test for Publication Bias
An adjusted rank correlation test is proposed as a technique for identifying publication bias in a meta-analysis, and its operating characteristics are evaluated via simulations. The test statistic is a direct statistical analogue of the popular "funnel-graph." The number of component studies in the meta-analysis, the nature of the selection mechanism, the range of variances of the effect size estimates, and the true underlying effect size are all observed to be influential in determining the power of the test. The test is fairly powerful for large meta-analyses with 75 component studies, but has only moderate power for meta-analyses with 25 component studies. However, in many of the configurations in which there is low power, there is also relatively little bias in the summary effect size estimate. Nonetheless, the test must be interpreted with caution in small meta-analyses. In particular, bias cannot be ruled out if the test is not significant. The proposed technique has potential utility as an exploratory tool for meta-analysts, as a formal procedure to complement the funnel- graph.
中文摘要
提出了一種調整秩相關檢驗作為一種在元分析中識別發表偏倚的技術，並通過模擬對其操作特徵進行了評估。檢驗統計量是流行的「漏鬥圖」的直接統計類似。元分析中原始研究的數量，選擇機制的性質，效應量估計值的方差範圍以及真正的潛在效應量均影響檢驗功效。對於具有75個原始研究的大型元分析，該檢驗具有很好的統計檢驗力，但對於具有25個原始研究的元分析，該檢驗僅具有中等統計檢驗力。但是，在許多低統計檢驗力情形中，匯總效應量估計中的偏差也相對較小。儘管如此，在小型元分析中必須謹慎解釋該檢驗。特別是，如果檢驗不顯著，不能排除發表偏差。提出的技術作為元分析的探索工具、補充漏鬥圖的正式程序具有潛在的實用性。