[GRADE: Methodology for formulating and grading recommendations in clinical practice].

Clinical practice guidelines (CPG) provide recommendations on the benefits and harms of different healthcare interventions. Proper CPG development and implementation can potentially reduce variability in clinical practice while improving its quality and safety. The GRADE system is used to assess the quality of evidence and to grade the strength of recommendations in the context of the development of CPGs, systematic reviews or health technology assessments. The aim of this article is to describe the main characteristics of the GRADE system through relevant examples in the context of primary care.