A new approach to outliers in meta-analysis

Baker, RD; Jackson, D

Abstract

The synthesis of evidence from trials and medical studies using meta-analysis is essential for Evidence Based Medicine. However, problematical outlying results often occur even under the random-effects model. We propose a model that allows a long-tailed distribution for the random effect, which removes the necessity for an arbitrary decision to include or exclude outliers. In this approach, they are included, but with a reduced weight. We also introduce a modification of the forest plot to show the downweighting of outliers. We illustrate the methodology and its usefulness by carrying out both frequentist and Bayesian meta-analyses using data sets from the Cochrane Collaboration.

Citation

Baker, R., & Jackson, D. (2008). A new approach to outliers in meta-analysis. Health Care Management Science, 11(2), 121-131. https://doi.org/10.1007/s10729-007-9041-8

• Journal Article Type: Article
• Publication Date: Jan 1, 2008
• Deposit Date: Nov 24, 2011
• Journal: Healthcare Management Science
• Print ISSN: 1386-9620
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 2
• Pages: 121-131
• DOI: https://doi.org/10.1007/s10729-007-9041-8
• Publisher URL: http://dx.doi.org/10.1007/s10729-007-9041-8