Systematic review

It answers a defined research question by collecting and summarising all empirical evidence that fits pre-specified eligibility criteria [1]. It is a thorough, comprehensive, and explicit way of interrogating the medical literature. It typically involves several steps, including asking an answerable question, identifying one or more databases to search, developing an explicit search strategy, selecting titles, abstracts, and manuscripts based on explicit inclusion and exclusion criteria, and abstracting data in a standardized format [2]. They often, but not always, use statistical techniques (meta-analysis) to combine results of eligible studies, or at least use scoring of the levels of evidence depending on the methodology used. While many systematic reviews are based on an explicit quantitative meta-analysis of available data, there are also qualitative systematic reviews which adhere to standards for gathering, analyzing and reporting evidence. A review of existing studies is often quicker and cheaper than embarking on a new study. Systematic reviews of randomized controlled trials are key in the practice of evidence-based medicine [3].

Bibliographic references:

[1] Ccace.ed.ac.uk. (2013). Systematic reviews and meta-analyses: a step-by-step guide | www.ccace.ed.ac.uk. [online] Available at: http://www.ccace.ed.ac.uk/research/software-resources/systematic-reviews-and-meta-analyses [Accessed 21 Jun. 2016].

[2] Researchcore.org. (2016). ResearchCore.org - What is the difference between a "systematic review" and a "meta-analysis"?. [online] Available at: http://www.researchcore.org/faq/answers.php?recID=5 [Accessed 21 Jun. 2016].

[3] Wikipedia. (2016). Systematic review. [online] Available at: https://en.wikipedia.org/wiki/Systematic_review [Accessed 21 Jun. 2016].