[The evidence (in) the evidence-based medicine].

Evidence-based medicine is a new approach to improve the transfer process of knowledge from research to medical practice. The assumption that only results of randomized controlled studies are evident is true for many but by far not for all clinical problems. As is demonstrated from one historical and many recent examples, there exists another but equally stringent method of proof which is based on an implicit historical comparison. This kind of evidence still has to be defined exactly in order to protect it from misuse by alternative medicine. The statement that only 20% of methods used in conventional medicine are [corrected] evidence-based cannot be substantiated. Methods and importance of meta-analyses are critically discussed as well as the meaning of the term publication bias. The new documentation- and information techniques will improve some steps in the transfer process. At the end it will be crucial whether the last step, the improvement of rationality in patient care, will be successful. This evidence still has to be demonstrated.