[Clinical practice guidelines development and implementation: an introduction].

Clinical Practice Guidelines (CPG), defined as "statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options", are tools currently present in every level of our health system. This article introduces guidelines development and implementation processes and it reviews the Chilean experience. The main stages in a CPG development are question formulation, search and analysis of the existing evidence related to those questions, and making judgments about that evidence in order to formulate recommendations for clinical practice. At the national level, guidelines development processes are conducted by the Ministry of Health, and even when recent evaluations show some good results, there are a number of aspects - such as applicability - that should be improved. On the other hand, CPG should be implemented using effective strategies in order to obtain changes in clinical practice and patients' outcomes. The existing evidence about the effects of the different implementation strategies shows modest and highly variable results. At the national level, there is a dearth of research about the design and evaluation of implementation strategies, and most of it has been focused in the evaluation of adherence to specific recommendations.