[GRADE guidelines: 2. Framing the question and deciding on important outcomes].

GRADE requires a clear specification of the relevant setting, population, intervention, and comparator. It also requires specification of all important outcomes - whether evidence from research studies is, or is not, available. For a particular management question, the population, intervention, and outcome should be sufficiently similar across studies so that a similar magnitude of effect is plausible. Guideline developers should specify the relative importance of the outcomes before gathering the evidence and again when evidence summaries are complete. In considering the importance of a surrogate outcome, authors should rate the importance of the patient-important outcome for which the surrogate is a substitute and subsequently rate down the quality of evidence for indirectness of outcome.