Revisões sistemáticas e metanálises

Ossos do Ofício partilha o seguinte sobre a revisão sistemática e a metanálise (e não meta-análise) - conceitos que se têm vindo a enraizar na literatura biomédica e que, inevitavelmente, alastrarão para os terrenos da paleopatologia. E são bem-vindos!

"A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made (Antman 1992, Oxman 1993).

The key characteristics of a systematic review are: 1) a clearly stated set of objectives with pre-defined eligibility criteria for studies; 2) an explicit, reproducible methodology; 3) a systematic search that attempts to identify all studies that would meet the eligibility criteria; 4) an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and 5) a systematic presentation, and synthesis, of the characteristics and findings of the included studies.

Many systematic reviews contain meta-analyses. Meta-analysis is the use of statistical methods to summarize the results of independent studies (Glass 1976). By combining information from all relevant studies, meta-analyses can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review. They also facilitate investigations of the consistency of evidence across studies and the exploration of differences across studies."

In:
Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1 [updated September 2008]. The Cochrane Collaboration, 2008. Available from www.cochrane-handbook.org.