[From evidence-based medicine to medicine-based evidence]

Medical practice is changing due to the more efficient use of the biomedical literature in making decisions on the care of individual patients. This constitutes a new scientific paradigm: evidence-based medicine (EBM). The factors that may explain the growing interest in EBM are awareness of variability in clinical practice, the importance of the efficacy, effectiveness and efficiency of new health technologies, and ease of access to biomedical literature (especially through the Internet). The main tools of EBM in clinical practice are the increasing production of systematic reviews of health interventions (Cochrane Collaboration, Agencies for Health Technology Assessment, Clinical Practice Guidelines) and critical appraisal of scientific documents [Critical Appraisal Skills Program (CASP) and Critically Appraised Topics banks].EBM emphasizes benefit to the individual patient and its key point is efficacy, since the principal source of information are clinical trials and meta-analyses in "ideal" clinical practice. Medicine-based evidence, as the complement of EBM, emphasizes benefit to society and its key point is the effectiveness and efficiency of health interventions, since the main information sources are measures of health-related quality of life and economic analyses in "normal" clinical practice. Total quality management aims at medicine based evidence.