Certainty of the evidence and definitions
| Certainty of the evidence | Definition |
| 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 |