Table 2– Quality of evidence and definitions
Quality of evidenceDefinition
High (⊕⊕⊕⊕)Further research is very unlikely to change our confidence in the estimate of effect
Moderate (⊕⊕⊕○)Further research is likely to have an important impact on our confidence in the effect and may change the estimate
Low (⊕⊕○○)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
Very low (⊕○○○)Any estimate of effect is very uncertain