Table 1.

An overview of the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system

GRADE—strength of evidence	GRADE—strength of recommendation
High quality Further research is very unlikely to change our confidence in the estimate of effect	The trade-offs Taking into account the estimated size of the effect for main outcomes, the confidence limits around those estimates and the relative value placed on each outcome
Moderate quality Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate	The quality of the evidence
Low quality Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate	Translation of the evidence into practice in a particular setting Taking into consideration important factors that could be expected to modify the size of expected effects
Very low quality Any estimate of effect is very uncertain	Uncertainty about the baseline risk for the population of interest