3.6. Use of surrogates

Guideline developers should consider surrogate outcomes only when high-quality evidence regarding important outcomes is lacking. When such evidence is lacking, guideline developers may be tempted to list the surrogates as their measures of outcome. This is not the approach GRADE recommends. Rather, they should specify the important outcomes and the associated surrogates they must use as substitutes. The necessity to substitute with the surrogate may ultimately lead to rating down the quality of the evidence because of indirectness.