Many Cochrane reviews compare more than two interventions, either implicitly or explicitly. Principled methods have been developed for analysing such networks so that both direct evidence from head-to-head comparisons and indirect evidence from studies with common comparators can be utilized.
The Comparing Multiple Interventions Methods Group has received funding from the Cochrane Methods Innovation Fund to set up three working groups to address three key issues related to these comparisons.
1 - Should I use an Overview or an Intervention Review?
We have conducted a broad consultation with Collaboration contributors and have produced:
- An editorial decision tree to assist in application of the recommendations
- A background paper explaining the rationale for each new recommendation
- A training event held in Oxford in March 2013 (Slides available here)
- A protocol template for a Cochrane Intervention Review that compares multiple interventions.
2 - What statistical methods are available
We held a 2 day meeting of statisticians, reviewers and CEU representatives in Bristol in 2013 (minutes and selected slides from the meeting are available here) and have produced:
3 - How to interpret and present results
We held a 2 day meeting of methodologists, reviewers and CEU representatives in Bristol in 2013 and have produced:
Meeting minutes with suggestions for Summary of Findings Tables and GRADE assessments for Cochrane Reviews incorporating a network meta-analysis.
A paper describing our proposed approach for applying GRADE ideas to network meta-analysis - Salanti G, Del Giovane C, Chaimani A, Caldwell DM, Higgins JPT. Evaluating the Quality of Evidence from a Network Meta-Analysis. PLoS ONE. 2014 Jul 3;9(7):e99682.