[Evidence-based medicine: context and relevance].

Currently, evidence-based medicine is subject of a controversial discussion. This review is focused on the different types of evidence in clinical medicine and elaborates the history and context of evidence-based medicine. Evidence-based medicine insists that the theoretical plausibility of a therapeutical concept alone does not substitute for the empirical proof of its efficacy. Evidence-based medicine emphasizes the necessity to complement the individual physician's clinical experience with valid external evidence. This evidence has to be obtained by laborious systematic reviews rather than the traditional fragmentary study of the literature. The Cochrane Collaboration stands for this concept. The application of evidence-based medicine links the individual patient's problems with external evidence by asking defined answerable questions and supplies criteria for the critical evaluation of the evidence found. Evidence-based medicine, however, is not devoid of problems and contradictions. Above all, it has to be subjected to its own criteria and has to prove its efficacy.