Assessing the Evidence on the Differential Impact of Menthol versus Non-menthol Cigarette Use on Smoking Dependence in the US Population: A Systematic Review and Meta-analysis.

Background: Menthol's effect on cigarette smoking behaviors is an intensely scrutinized US public health issue. This systematic review and meta-analysis examined the question: Does menthol cigarette use have a differential impact on smoking dependence compared with non-menthol cigarette use? Methods: We consulted 6 databases from inception to October 15, 2021. We included articles comparing menthol versus non-menthol cigarette smokers against predefined smoking dependence outcomes. Risk of bias was assessed using the AHRQ Evidence-Based Practice Center approach. We applied a random-effects model to pool adjusted odds ratios. Results: We synthesized 37 demographically adjusted studies. Meta-analytic results suggested non-menthol smokers were equally/more likely to report daily versus non-daily smoking; menthol use was associated with needing a cigarette within one hour; cigarettes per day was not associated with menthol use; menthol use was associated with a low (vs high) Heaviness of Smoking Index score; and results were either non-significant or associated menthol use with lower TTFC. Conclusions: Despite consistently good or fair quality adjusted studies across several measures, results were discordant depending on measures used and means of measurement. Overall, the evidence is insufficient to draw clear conclusions on a differential association between menthol (vs non-menthol) cigarette use and smoking dependence.