What a Baujat plot shows
A Baujat plot is a diagnostic scatterplot used in meta-analysis to identify studies that disproportionately drive results. Each study is plotted as a point with two coordinates: the horizontal axis shows the study's contribution to overall heterogeneity (typically its contribution to the Q statistic), and the vertical axis shows its influence on the pooled effect estimate.
Studies sitting in the upper-right region both add a lot of heterogeneity and shift the combined result substantially, marking them as the most influential and worth closer inspection. It was introduced by Baujat and colleagues in 2002.
How analysts use it
The plot supports sensitivity analysis. Rather than blindly removing outliers, analysts use the Baujat plot to flag candidate studies, then check whether features such as study design, sample size, or risk of bias explain their outsized effect.
It is one of several influence diagnostics, often used alongside leave-one-out analyses and forest plots, and is available in meta-analysis software such as the metafor package in R. The goal is transparency about which studies the conclusions actually depend on.