Notes on certainty of evidence assessment (scores generated in worksheet 2) 2. 3. 1. Consider lowering or raising Final level of Establish initial level of confidence confidence level of confidence design Initial confidence Reasons for considering lowering Confidence in an estimate of or raising confidence in an estimate of effect effect across those considerations if* Higher if*   High Risk of Bias Strong association Randomised trials High confidence (4) -1 Serious +1 Strong, no plausible -2 Very serious confounders Inconsistency +2 Very strong, no major threats to validity -1 Serious Moderate Dose response -2 Very serious Indirectness +1 Evidence of a gradient Non-randomised Low -1 Serious All plausible Low -2 Very serious evidence confidence (2) Imprecision confounding & bias -1 Serious Would reduce a -2 Very serious demonstrated effect Publication bias OR -1 Likely Would suggest a -2 Very likely spurious effect if no effect was observed Very low +1 All plausible confounders or bias would decrease the size of the effect if there is evidence of an effect, or increase it if there is evidence of no harmful effect (safety)
Notes on certainty of evidence assessment (scores generated in worksheet 2) 1. Establish initial level of confidence 2. Consider lowering or raising level of confidence 3. Final level of confidence design Initial confidence in an estimate of effect Reasons for considering lowering or raising confidence Confidence in an estimate of effect across those considerations  if*  Higher if* Randomised trials High confidence (4) Risk of Bias -1 Serious -2 Very serious Inconsistency -1 Serious -2 Very serious Indirectness -1 Serious -2 Very serious Imprecision -1 Serious -2 Very serious Publication bias -1 Likely -2 Very likely Strong association +1 Strong, no plausible confounders +2 Very strong, no major threats to validity Dose response +1 Evidence of a gradient All plausible confounding & bias Would reduce a demonstrated effect OR Would suggest a spurious effect if no effect was observed +1 All plausible confounders or bias would decrease the size of the effect if there is evidence of an effect, or increase it if there is evidence of no harmful effect (safety) High Moderate Non-randomised evidence Low confidence (2) Low Very low