CRE has reviewed the studies commissioned by FDA on menthol. CRE’s review focuses on initiation/cessation studies.
Major conclusions:
1. Only one study investigated the association between smoking initiation and use of menthol cigarettes . This was a secondary analysis of the American Legacy Longitudinal Tobacco Use Reduction Study (ALLTURS), a large longitudinal school-based survey of middle school and high school youth conducted in three waves from 2000 through 2003. In this study, subjects were aged 12 to 17 at baseline. It found that starting smoking with menthol (initiating first to menthol) is associated with each of the six indicators of smoking initiation in this study. However, this relationship was not adjusted for well known confounders including race, family income, and parents/caregivers’ education and smoking status.
2. The other eight studies investigated the association between smoking cessation and use of menthol cigarettes among adults (aged 18 and over). Four of them were longitudinal clinical trials or longitudinal observational studies with sample size less than 500–a size often considered to small for population level inferences.
3. One of the studies found that menthol cigarette users had higher rates of smoking cessation than non-menthol users with no statistical significance; other studies reviewed found the reverse relationship with no statistical significance; and another study found that while use of menthol cigarettes had no effect on smoking cessation, menthol cigarette use, race, and medication interacted with each other to affect smoking cessation outcomes
4. Three of the studies on adults were large population-based surveys with complex designs: two of them were panel surveys; one was a cross-sectional survey. The two panel survey studies had three measures of smoking cessation: quit attempts (yes/no), cessation, and cessation among those making a quit attempt but definitions for these measures in the two studies were different which make the conclusions non-comparative. For example, one study in defined a quitter as a person who didn’t smoke any cigarettes in the last six months while another study in defined a quitter as a person who no longer smoked on at least a monthly basis. Both studies found that overall menthol smokers are equally as likely as non-menthol smokers to try to quit smoking and successfully quit smoking
CRE will look forward to the reports by the study authors at the forthcoming TPSAC meeting.
CRE concludes that it will be difficult for TPSAC to conclude that menthol has an adverse impact on smoking initiation/cessation.