Summary: In this final article in the series of resource documents aimed at helping clinicians understand the ways in which findings from research studies are reported in the literature, secondary sources of evidence are explained. Systematic reviews and meta-analyses are designed to bring together all of the relevant primary sources of research evidence in a particular topic area, and disseminate this in a format that informs clinicians, patients, healthcare purchasers and guideline developers. This attempt to facilitate evidence-based practice however, is thwarted in part by clinicians’ and other end-users’ understandable difficulty in interpreting these types of evidence. Meta-analysis is positioned at the pinnacle of the evidence hierarchy, at least in terms of informing decisions regarding the efficacy of a treatment intervention. It is imperative that clinicians understand systematic reviews and meta-analyses if evidence-based practice is to be implemented in the clinical setting.