Table 1

Certainty of evidence grades

GradeLetterDefinition
HighAWe are very confident that the true effect lies close to that of the estimate of the effect
ModerateBWe are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
LowCOur confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect.
Very lowDWe have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect