A comparison of methods to detect publication bias for meta-analysis of continuous data

Abstract

Publication bias is a serious problem in meta-analysis. Various methods have been developed to detect the presence of publication bias in meta-analysis. These methods have been assessed and compared in many dichotomous studes utilizing the log-odds ratio as the measure of effect. This study evaluates and compares the performance of three popular methods, namely the Egger's linear regression method, the Begg and Mazumdar's rank correlation method and the Duval and Tweede's trim and fill method on meta-analysis of continuous data. The data comprised simulated meta-analyses with different levels of primary studies in the absence and presence of induced publication bias. The performances of these methods were measured through the power and type 1 error rate for the tests. The results suggest the trim and fill method to be superior in terms of its ability to detect publication bias when it exists, even in presence of only 5% unpublished studes. However, this method is not recommended for large meta-analysis as it produces high rate of false-positive results. Both linear regression and rank correlation method performed relatively well in moderate bias but should be avoided in small meta-analysis as their power is vely low in this data. © 2012 Asian Network for Scientific Information.