Outlier and influence diagnostics for meta-analysis.

Authors :: Viechtbauer W
Cheung MW
Source :: Research synthesis methods [Res Synth Methods] 2010 Apr; Vol. 1 (2), pp. 112-25. Date of Electronic Publication: 2010 Oct 04.
Publication Year :: 2010
Abstract: The presence of outliers and influential cases may affect the validity and robustness of the conclusions from a meta-analysis. While researchers generally agree that it is necessary to examine outlier and influential case diagnostics when conducting a meta-analysis, limited studies have addressed how to obtain such diagnostic measures in the context of a meta-analysis. The present paper extends standard diagnostic procedures developed for linear regression analyses to the meta-analytic fixed- and random/mixed-effects models. Three examples are used to illustrate the usefulness of these procedures in various research settings. Issues related to these diagnostic procedures in meta-analysis are also discussed. Copyright © 2010 John Wiley & Sons, Ltd.<br /> (Copyright © 2010 John Wiley & Sons, Ltd.)