Network Meta-Analysis for Complex Social Interventions: Problems and Potential

Abstract

When multiple interventions exist for the same problem, evidence-based decision making requires clear and systematic syntheses of available evidence to determine which interventions are most effective. Network meta-analysis extends standard pairwise meta-analytic models to allow direct and indirect evidence from primary studies comparing alternative interventions to be statistically combined in a single analysis. The use of indirect evidence can increase the precision of estimates and allow the relative effectiveness of interventions to be estimated even if particular interventions have never been directly compared in primary studies. The validity of network meta-analyses requires assumptions that may be difficult to verify in reviews of complex social interventions, and the method has rarely been applied outside of medicine. This paper provides a nontechnical introduction to network meta-analysis and to some of the advantages and challenges involved in its application to complex social interventions. We conclude that network meta-analysis is an important and needed tool for social researchers. However, we also find that applications to complex social interventions require more extensive and theory-driven assessments of validity than those needed for either pairwise meta-analyses or for applications to biomedical treatments. Existing guidance on reporting of network meta-analyses could be usefully expanded to require more detailed reporting of these additional measures in the case of complex interventions. CR - Copyright © 2013 Society for Social Work and Research