This is an archived version of the Handbook. For the current version, please go to

16.5  Studies with more than two intervention groups

16.5.1 Introduction

16.5.2 Determining which intervention groups are relevant

16.5.3 Assessing risk of bias in studies with more than two groups

16.5.4 How to include multiple groups from one study

16.5.5 Heterogeneity considerations with multiple-intervention studies

16.5.6 Factorial trials