[Evidence-based medicine].

Evidence-based medicine has been described as a new approach to teaching and practicing clinical medicine. Although the search for evidence is an established practice among physicians, what is being proposed is the systematic gathering and critical interpretation of data, which can then be used in the appropriate context. The main objective is to provide better care for patients. This is accomplished by transforming clinical problems in specific questions to be answered by searching the literature for the levels of evidence favoring the possible interventions for one particular case. This has to be done in a systematic and conscientious fashion. Through its method, evidence-based medicine places less value on clinical experience, the study understanding of pathophysiology, and common sense; instead, it emphasizes observation, levels of evidence, and critical interpretation of original literature. In this manner, evidence-based medicine may be seen by the authoritarian physician as a threat. Other obstacles to the acceptance of the method include lack of time and lack of familiarity with computers. One important limitation of evidence-based medicine is the incomplete or contradictory evidence available in many areas of clinical medicine, or the so-called "grey zones". We outline the main aspects of evidence-based medicine, expecting a growing interest among brazilian physicians for this useful clinical tool.