Disclosures This review was funded by a contract from Pfizer Inc.
Understanding heterogeneity in meta-analysis: the role of meta-regression
Version of Record online: 14 SEP 2009
© 2009 Blackwell Publishing Ltd
International Journal of Clinical Practice
Volume 63, Issue 10, pages 1426–1434, October 2009
How to Cite
Baker, W. L., Michael White, C., Cappelleri, J. C., Kluger, J., Coleman, C. I. and From the Health Outcomes, Policy, and Economics (HOPE) Collaborative Group (2009), Understanding heterogeneity in meta-analysis: the role of meta-regression. International Journal of Clinical Practice, 63: 1426–1434. doi: 10.1111/j.1742-1241.2009.02168.x
- Issue online: 14 SEP 2009
- Version of Record online: 14 SEP 2009
Background: Meta-regression has grown in popularity in recent years, paralleling the increasing numbers of systematic reviews and meta-analysis published in the biomedical literature. However, many clinicians and decision-makers may be unfamiliar with the underlying principles and assumptions made within meta-regression leading to incorrect interpretation of their results.
Aims: This paper reviews the appropriate use and interpretation of meta-regression in the medical literature, including cautions and caveats to its use.
Materials & Methods: A literature search of MEDLINE (OVID) from 1966-February 2009 was conducted to identify literature relevant to the topic of heterogeneity and/or meta-regression in systematic reviews and meta-analysis.
Results: Meta-analysis, a statistical method of pooling data from studies included in a systematic review, is often compromised by heterogeneity of its results. This could include clinical, methodological or statistical heterogeneity. Meta-regression, said to be a merging of meta-analytic and linear regression principles, is a more sophisticated tool for exploring heterogeneity. It aims to discern whether a linear relationship exists between an outcome measure and on or more covariates. The associations found in a meta-regression should be considered hypothesis generating and not regarded as proof of causality.
Conclusions: The current review will enable clinicians and healthcare decision-makers to appropriately interpret the results of meta-regression when used within the constructs of a systematic review, and be able to extend it to their clinical practice.