Practice guidelines, a new reality in medicine. II. Methods of developing guidelines.

Current methods for developing practice guidelines include informal consensus development, formal consensus development, evidence-based guideline development, and explicit guideline development. Informal consensus development is the oldest and most common approach, but guidelines produced in this manner are often of poor quality and lack adequate documentation of methods. Formal consensus development uses a systematic approach to assess expert opinion and to reach agreement on recommendations. Evidence-based guideline development links recommendations directly to scientific evidence of effectiveness; rules of evidence are emphasized over expert opinion in making recommendations. Explicit guideline development clarifies the rationale by specifying the potential benefits, harms, and costs of available interventions; estimating the possibility of the outcomes; and comparing the desirability of the outcomes based on patient preferences. Steps in the development of practice guidelines include introductory decisions (selection of topic and panel members, clarification of purpose); assessments of clinical appropriateness (review of scientific evidence and expert opinion); assessment of public policy issues (resource limitations, feasibility issues); and guideline document development and evaluation (drafting of document, peer review, and pretesting).