3.1. General approach

Outcomes may include survival (mortality), clinical events (e.g. stroke or myocardial infarction), patient-reported outcomes (e.g. specific symptoms, quality of life), adverse events, burdens (e.g. demands on caregivers, frequency of tests, restrictions on lifestyle) and economic outcomes (e.g. cost and resource use). It is critical to identify both outcomes related to adverse effects/harm as well as outcomes related to effectiveness.

Review authors should consider how outcomes should be measured, both in terms of the type of scale likely to be used and the timing of measurement. Outcomes may be measured objectively (e.g. blood pressure, number of strokes) or subjectively as rated by a clinician, patient or carer (e.g. disability scales). It may be important to specify whether measurement scales have been published or validated.

GRADE specifies three categories of outcomes according to their importance. Guideline developers must, and authors of systematic reviews are strongly encouraged to specify all potential patient-important outcomes as the first step in their endeavour. The guideline development group should classify outcomes as:

• Critical;
• Important, but not critical;
• Of limited importance.

The first two classes of outcomes will bear on guideline recommendations; the third may or may not. Ranking outcomes by their relative importance can help to focus attention on those outcomes that are considered most important, and help to resolve or clarify disagreements. GRADE recommends to focus on a maximum of 7 critical and/or important outcomes.

Guideline developers should first consider whether particular desirable or undesirable consequences of a therapy are important to the decision regarding the optimal management strategy, or whether they are of limited importance. If the guideline panel thinks that a particular outcome is important, then it should consider whether the outcome is critical to the decision, or only important, but not critical. To facilitate ranking of outcomes according to their importance guideline developers as well as authors of systematic reviews may choose to rate outcomes numerically on a 1 to 9 scale (7 to 9 – critical; 4 to 6 – important; 1 to 3 – of limited importance) to distinguish between importance categories.

For each recommendations GRADE proposes to limit the number of outcomes to a maximum of 7.