Table 5.2 GRADE certainty ratings and their interpretation symbols^a

 ⊕  ⊕  ⊕  ⊕ High: We are very confident that the true effect lies close to that of the estimate of the effect

 ⊕  ⊕  ⊕ Moderate: We 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

 ⊕  ⊕ Low: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect

 ⊕ Very low: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect