Table 1.

Level of quality of evidence (GRADE)

Quality level
High quality
• There are consistent findings among at least 75% of participants. • Consistent low risk of bias, with accurate data and no known or suspected publication bias. • Future studies are unlikely to change the estimated results.
Moderate quality
• There is moderate confidence in the estimated effect. • Future studies are likely to have a significant impact on the confidence of the treatment effect estimation and may alter the treatment effect estimate.
Low quality
• Confidence in the treatment effect is limited. • Additional research is very likely to have a significant impact on the confidence of the estimated treatment effect and it is likely to change the estimate.
Very low quality
• Confidence in the estimated treatment effect is very limited. • Results are uncertain.