Objective: Systematic reviews and meta-analyses are increasingly frequently used in the evaluation of medical treatments. This review explains the principles of the methodology, significance and limitations of systematic reviews.
Method: Short review article.
Results: In contrast to conventional reviews, systematic reviews use a structured approach in retrieving, analyzing and interpreting the evidence. A comprehensive search strategy is applied to identify all relevant trials. Study selection and data extraction is performed independently by at least two reviewers. The data are usually synthesized in a meta-analysis applying statistical methods to examine homogeneity. Funnel plots and other statistical methods are applied to detect publication bias.
Conclusion: Due to the enormous amount of scientific information published every year, systematic reviews and meta-analyses have become indispensable methods for the evaluation of medical treatments.