Use of network meta-analysis in systematic reviews: a survey of authors

BACKGROUND The reporting of network meta-analysis in systematic reviews has increased rapidly since 2009. This qualitative study was undertaken to identify authors' perceptions of the use of these methods and of what standards for conduct and reporting should apply. METHODS This is a survey of authors of systematic reviews reporting network meta-analysis. RESULTS The response rate was 32 % of the authors contacted, with these authors responsible for 34 % of the fully published systematic reviews identified within the period searched. Almost all authors would use the method again. Elements of reporting standards were proposed. Responses revealed some tensions between the view that use of network meta-analysis should be more easily accessible, particularly in the form of software tools, and concern that there is some inappropriate use of the methods, which wider use and greater accessibility could exacerbate. CONCLUSIONS Authors demonstrated strong support for adoption of standards for conduct and reporting. The elements of reporting standards proposed are consistent with those included in the 2015 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension statement. Adoption of standards for conduct and reporting will be a significant step towards clarifying what is appropriate use of the methods and what is not. This should be followed by the development of a critical appraisal tool to support end users of systematic reviews reporting network meta-analysis.