Methods for including information from multi-arm trials in pairwise meta-analysis

Res Synth Methods. 2017 Dec;8(4):392-403. doi: 10.1002/jrsm.1259. Epub 2017 Aug 25.


Systematic reviewers conducting pairwise meta-analyses sometimes encounter multi-arm studies. To include these studies, and to avoid a unit-of-analysis error, often two or more arms are combined or the control arm is split. In this tutorial, we present 5 different approaches that can be used. Particularly, we present a novel approach (method 4) that to the best of our knowledge has not been presented before. We demonstrate their application on 3 selected data sets, discuss their scope of application and their advantages and limitations, and give recommendations.

Keywords: multi-arm trials; multiplicity; network meta-analysis; pairwise meta-analysis.

MeSH terms

  • Acupuncture Therapy / methods*
  • Algorithms
  • Breast Neoplasms / therapy*
  • Clinical Trials as Topic*
  • Databases, Factual
  • Female
  • Humans
  • Meta-Analysis as Topic*
  • Models, Statistical
  • Pelargonium / chemistry
  • Research Design*
  • Review Literature as Topic*