Systematic review and meta-analysis as a support tools for research and clinical practice

Systematic reviews are secondary investigations that compile published results that have been obtained from studies involving human subjects. Meta-analysis is the term used to describe the carrying out of statistical analysis of the combination of the results of two or more original studies, which had to be selected from a systematic review. In this way, a meta-analysis cannot exist without a systematic review. Systematic reviews arise due to the exponential increase in the information; to provide all health personnel with a study that critically analyzes the results and discriminates those that may be useful in clinical practice. Systematic reviews are one of the fundamental tools in evidence-based medicine, in which two of the main steps refer to both the search and the critical analysis of the studies, which shall support medical decisions on aspects that are mainly related to diagnosis, treatment, or prognosis. On the other hand, systematic reviews have been essential for some time now when developing evidence-based clinical practice guidelines and they can be used to make decisions on health policies. The methodology for performing and interpreting systematic reviews and meta-analysis is described in this article.