Longitudinal analysis of associations between reasons for electronic cigarette use and change in smoking status among adults in the Population Assessment of Tobacco and Health Study.

Introduction: Electronic cigarette (ECIG) use and changes in cigarette smoking status may be influenced by self-reported reasons for using ECIGs.

Methods: We analyzed adult current and former cigarette smokers who were also current or former ECIG users at Wave 1 (n=3044) using Wave 1 and Wave 2 Population Assessment of Tobacco and Health Study data (2013-2015). Prevalence of reporting 13 reasons for ECIG use at Wave 1 was examined and weighted logistic regressions were conducted predicting smoking status changes from Wave 1 to Wave 2.

Results: Reasons for ECIG use ranged from 18.1% (people in the media/public figures use them) to 82.5% (they might be less harmful to people around me than cigarettes). From Wave 1 to Wave 2, 27.2% of former smokers (n=249) became current smokers and 11.6% of current smokers (n=246) became former smokers. Among Wave 1 former smokers, using ECIGs because of the availability of flavors (AOR=0.57, 95% CI=0.39-0.85) or because they don't smell (AOR=0.64, 95% CI=0.42-0.97) was associated with lower odds of relapse to smoking, but using ECIGs because using them helps people quit smoking (AOR=1.55, 95% CI=1.01-2.38) was associated with greater odds of relapse. Among Wave 1 current smokers, using ECIGs because they can be used where smoking is not allowed (AOR=0.56, 95% CI=0.38-0.85) was associated with reduced odds of quitting cigarettes.

Conclusions: Some reasons for ECIG use are associated with changes in self-reported smoking status. Researchers should examine ECIG user characteristics when assessing associations between ECIG use and smoking status transitions.

Implications: Given that certain reasons for ECIG use, such as using ECIGs in locations are where smoking is not allowed, may inhibit smoking reduction, policies may be developed to prevent ECIG use in locations where smoking is banned. Additionally, because certain reasons for ECIG use may aid in relapse prevention, such as availability of desired flavors, efforts should be made to identify ECIG device characteristics that are appealing to smokers but not youth or non-tobacco users. These results provide support for future research on reasons for ECIG use to inform regulatory policies.