Understanding and interpreting systematic review and meta-analysis results

An overwhelming amount of scientific evidence is published in the medical and dental literature every year. As a consequence, it has become increasingly difficult for clinicians to be up-to-date. Systematic reviews and meta-analysis have become the cornerstone of Evidence-Based Health care. However, the methodology used to search and critically appraise the literature and the statistical methods used to combine results from different studies in an overall estimate are poorly understood. The aim of the present chapter is to provide an overview of the methods used to combine the results of several studies. The chapter will focus on the application and interpretation of meta-analytic methods.