[Evidence-based medicine: benefits, inconveniences and risks of a new dogma]

Progress in biostatistics and epidemiology during twentieth century contributed to clinical research development. Controversy about the real role of these disciplines in validating clinical activity isn't new: in history of medicine there are evidence since nineteenth century. Evidence-based medicine is a recent methodology to evaluate clinical investigation that begins to be considered gold standard in knowledge and medical practice evaluation. Its method is based mainly in systematized meta-analyses or revisions through which tries to offer answers to concrete clinical questions. These answers are, however, clearly of statistical nature. It is not useful in clinical practice but rather should be focused to teaching-learning process, as well as on the creation of work regulations. Its application implies certain benefits, but also several practical difficulties in cultural, academic and socio-economic fields, due to its use without discriminating. Thus, its correct use is a challenge to contemporary medicine.