Table 2 GRADE levels of certainty of the evidence (Balshem et al. 2011)
Symbol | Quality level | Interpretation |
|---|---|---|
⨁⨁⨁⨁ | High | The true effect lies close to that of the estimated effect |
⨁⨁⨁◯ | Moderate | The true effect is likely to be close to the estimated effect, but there is a possibility that it is substantially different |
⨁⨁◯◯ | Low | The true effect might be substantially different from the estimated effect |
⨁◯◯◯ | Very low | The true effect is likely to be substantially different from the estimated effect |