First e-cigarette flavor and device type used: Associations with vaping persistence, frequency, and dependence in young adults.

INTRODUCTION Type of e-cigarette flavoring and device during first use might differentiate later e-cigarette use and dependence. This retrospective cross-sectional study examined associations of recalled first nicotine vaping device and flavor used with current vaping frequency/dependence. METHODS A young adult cohort from Los Angeles, California, USA completed web-based surveys (N=2553). Using cross-sectional data from 971 reporting ever vaping nicotine, multivariable hurdle regressions tested associations between recalled first flavor (fruit/sweet, menthol/mint, other) and device (Juul, disposable, mod, box, pod, pen, other) vaped with past-30-day vaping status (yes/no) and frequency (1-30 days), and with any vaping dependence symptoms (yes/no) and count (1-10 symptoms). RESULTS The most common first-flavor was sweet (71%); the most common first-device was a vape pen (37%), then Juul (22%). First-flavor of mint/menthol (vs. other; adjusted odds ratio [AOR]: 2.22[95%CI=1.16-4.25]), and first-device mod (AOR=2.40[95%CI=1.34-4.31]) and non-Juul pod (2.64[95% CI=1.41-4.92]) (vs. pen) were associated with past-30-day vaping, and twice as many vaping days (ARRs [Adjusted rate ratios] range: 1.96-2.12;ps<0.05). First flavor of mint/menthol (vs. other; AOR: 1.95[95% CI=1.003-3.79) and first device mod, box, non-juul pod and other (AORs range: 2.36-4.01;ps<0.05) were associated with nicotine dependence. First device Juul, mod, box and non-Juul pod were also associated with more dependence symptoms (ARRs range:1.38-1.59;ps<0.05). CONCLUSIONS Exposure to mint/menthol and certain devices (mod, box, Juul and non-juul pods) at first e-cigarette use may be associated with more frequent e-cigarette use and nicotine dependence symptoms in young adulthood. Mint/menthol and certain devices warrant consideration in regulation of e-cigarettes based on product characteristics. IMPLICATIONS Characteristics (flavor and device type) of first e-cigarette product used were associated with higher usage and more dependence. Pending replication with prospective designs, the findings suggest certain flavors (mint/menthol) and devices (pods, mods) merit consideration in regulation because of their possible link with continued use and dependence among young people.