Table 2 Levels of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE)
Level | Definition | Implications |
|---|---|---|
High (⨁⨁⨁⨁) | We are very confident that the true effect lies close to that of the estimate of the effect | Future research is unlikely to change confidence in the estimated effect |
Moderate (⨁⨁⨁O) | 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 | Future research will likely have a major impact on confidence in the estimated effect and may change this estimate |
Low (⨁⨁OO) | Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect | Future research will likely have a major impact on confidence in the estimated effect and will likely change this estimate |
Very low (⨁OOO) | We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of the effect | Any estimate of an effect is very uncertain |