This article is published in Research Synthesis Methods as a special issue on Network Meta-analysis, edited by Georgia Salanti, University of Ioannina, Greece.
Special Issue Paper
Using network meta-analysis to evaluate the existence of small-study effects in a network of interventions
Article first published online: 31 MAY 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Research Synthesis Methods
Special Issue: Special issue on Network Meta-analysis
Volume 3, Issue 2, pages 161–176, June 2012
How to Cite
Chaimani, A. and Salanti, G. (2012), Using network meta-analysis to evaluate the existence of small-study effects in a network of interventions. Res. Synth. Method, 3: 161–176. doi: 10.1002/jrsm.57
- Issue published online: 20 JUL 2012
- Article first published online: 31 MAY 2012
- Manuscript Accepted: 17 FEB 2012
- Manuscript Revised: 1 FEB 2012
- Manuscript Received: 10 AUG 2011
- uropean Research Council. Grant Number: IMMA 260559
- funnel plot;
- publication bias;
- sponsorship bias;
- optimism bias;
- selective reporting bias
Suggested methods for exploring the presence of small-study effects in a meta-analysis and the possibility of publication bias are associated with important limitations. When a meta-analysis comprises only a few studies, funnel plots are difficult to interpret, and regression-based approaches to test and account for small-study effects have low power. Assuming that the cause of funnel plot asymmetry is likely to affect an entire research field rather than only a particular comparison of interventions, we suggest that network meta-regression is employed to account for small-study effects in a set of related meta-analyses. We present several possible models for the direction and distribution of small-study effects and we describe the methods by re-analysing two published networks. Copyright © 2012 John Wiley & Sons, Ltd.