[Statistical methods for detecting and adjusting for publication bias]

Abstract

Publication bias in meta-analysis occurs if the probability of publication depends on the estimated treatment effect and the precision/size of a study. In this article we describe the funnel plot as a graphical method to evaluate the presence of publication bias. Furthermore, tests of publication bias based on funnel plots are explained, and methods are presented that estimate treatment effects adjusted for publication bias. The article closes with a critical discussion of the various statistical methods.