Systematic review and meta-analysis: a primer

The use of an evidence-based approach to practice requires "the integration of best research evidence with clinical expertise and patient values", where the best evidence can be gathered from randomized controlled trials (RCTs), systematic reviews and meta-analyses. Furthermore, informed decisions in healthcare and the prompt incorporation of new research findings in routine practice necessitate regular reading, evaluation, and integration of the current knowledge from the primary literature on a given topic. However, given the dramatic increase in published studies, such an approach may become too time consuming and therefore impractical, if not impossible. Therefore, systematic reviews and meta-analyses can provide the "best evidence" and an unbiased overview of the body of knowledge on a specific topic. In the present article the authors aim to provide a gentle introduction to readers not familiar with systematic reviews and meta-analyses in order to understand the basic principles and methods behind this type of literature. This article will help practitioners to critically read and interpret systematic reviews and meta-analyses to appropriately apply the available evidence to their clinical practice.