[Meta-analysis as a tool for evaluation of evidence].
In these days, more than one clinical trial is mostly performed to evaluate a new treatment or therapeutic intervention. This necessitates a combined evaluation of their results. An integration of evidence from several trials is also helpful to determine the actual knowledge. These are the main goals of meta-analyses. Since the end of the 80s meta-analyses are widely used in clinical research. At the beginning of a meta-analysis, a protocol has to be developed. Similar to a protocol of a clinical trial, the inclusion and exclusion criteria for trials, the hypotheses and the planned analyses have to be fixed. After a careful localization of trials, a combined statistical analysis is performed. An investigation of heterogeneity, i.e., differences between study results, is indispensable. During the last years, the tool meta-analysis has been criticized. The criticism mainly results from poorly conducted meta-analyses which generated results without prespecifying hypotheses or which merely combined study results. Well-planned meta-analyses, on the contrary, have an increasing influence in clinical research.
Koch
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Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM), Berlin. A.Koch@bfarm.de
Ziegler
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D002985:Clinical Protocols / Q000592:standards; D002986:Clinical Trials as Topic / Q000592:standards*; D003627:Data Interpretation, Statistical; D006801:Humans; D015201:Meta-Analysis as Topic; D012107:Research Design / Q000592:standards