Understanding systematic reviews and meta-analyses.

Systematic reviews and meta-analyses of randomised controlled trials are increasingly being used by healthcare professionals, policy makers, budget holders and patients to inform decisions relating to the effectiveness of competing interventions or healthcare delivery programmes. Well-conducted systematic reviews can help to address the challenge presented by the ever-increasing volume of original research.1 In 2009, DTB published an article that introduced the basic concepts relating to systematic reviews and meta-analyses.2 In this article we build on our original article and take a more detailed look at what a reader should be aware of when reading a systematic review to ensure that the appropriate techniques have been used.