Table 1

Grading evidence and recommendations (adapted from GRADE system3)

Grading of evidenceNotesSymbol
High qualityFurther research is very unlikely to change our confidence in the estimate of effectA
Moderate qualityFurther research is likely to have an important impact on our confidence in the estimate or effect and may change the estimateB
Low or very low qualityFurther research is very likely to have an important impact on our confidence in the estimate or effect and is likely to change the estimate. Any estimate of effect is uncertainC
Grading recommendationNotesSymbol
Strong recommendationFactors influencing the strength of the recommendation included the quality of the evidence, presumed patient-important outcomes and cost1
Weaker recommendationVariability in preferences and values, or more uncertainty: more likely a weak recommendation is warranted
Recommendation is made with less certainty: higher cost or resource consumption
2