Inclusion Criteria | Exclusion Criteria | |
---|---|---|
Population | • Youth and adults • Current or former smokers with explicit use of (or stated preference for) menthol or non-menthol cigarettes; studies of non-smokers were eligible if they reported a measure of initiation • United States residents | • Studies of never-smokers at any time point • Studies of only non-United States residents |
Comparisons | • Menthol versus non-menthol • Delivery of nicotine via traditional cigarettes | • Studies reporting only menthol or non-menthol or not directly comparing menthol with non-menthol • Studies of non-traditional tobacco deliverya |
Outcomes | • Duration of abstinence; quit attempts (any quit attempts; number of quit attempts per person); rate of abstinence/quitting (including but not limited to prolonged abstinence [PA], point prevalence abstinence [PPA], identifiable cigarette type [menthol versus non-menthol] smoked before quitting, and being a former smoker [versus current smoker]); Change in smoking quantity/frequency; return to smoking/relapse | • Any other outcomes |
Study Designsb | • Randomized and non-randomized controlled trials • Cross-sectional, case-control, and cohort studies • Letters and editorials containing original data not available elsewhere were eligible | • Reviews, case reports, editorials, and letters not containing original data |