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Table 2 Strength of Evidence Grades and Definitions

From: Assessing the evidence on the differential impact of menthol versus non-menthol cigarette use on smoking cessation in the U.S. population: a systematic review and meta-analysis

Grade Interpretation Description
High Very confident that the estimate of effect lies close to the true effect for this outcome. The body of evidence has few or no deficiencies.
We believe that the findings are stable, that is, another study would not change the conclusions.
Moderate Moderately confident that the estimate of effect lies close to the true effect for this outcome. The body of evidence has some deficiencies.
We believe that the findings are likely to be stable, but some doubt remains.
Low Limited confidence that the estimate of effect lies close to the true effect for this outcome. The body of evidence has major or numerous deficiencies (or both).
We believe that additional evidence is needed before concluding either that the findings are stable or that the estimate of effect is close to the true effect.
Insufficient No evidence; unable to estimate an effect, or no confidence in the estimate of effect for this outcome. No evidence is available or the body of evidence has unacceptable deficiencies, precluding reaching a conclusion.