[The GRADE system: a change in the way of assessing the quality of evidence and the strength of recommendations].

Individual clinicians and organizations making health care decisions should not only consider the magnitude of the benefits and harms of different courses of action (interventions), but also the confidence we can have in those estimates. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach offers a systematic and transparent way to summarize the evidence, to rate the confidence we can have in the effects of the interventions and to move from evidence to recommendations. The GRADE approach has been adopted by several organizations worldwide, including the World Health Organization and the Cochrane Collaboration. In Chile, this approach has already been used by guidelines produced by the Chilean Ministry of Health. In this paper we describe the core concepts of the GRADE approach to rate the quality of the evidence and to grade the strength of recommendations. As clinicians, being familiar with such concepts may be helpful to make decisions informed by the best available evidence.