Device and liquid characteristics used with sweet, menthol/mint, and tobacco ENDS liquid flavors: The population-based VAPER study

Introduction: Electronic nicotine delivery system (ENDS) device and liquid characteristics (e.g., wattage, nicotine concentration) are diverse and important in determining product appeal, aerosol volume/nicotine levels, and toxicity. Little is known about how device and liquid characteristics vary by flavor; we address this gap to identify potential regulatory implications.Methods: Data are from a longitudinal cohort study (Waves 2 and 3; December 2020-December 2021) of adult (>= 21 years) U.S. ENDS users (>= 5 days of use/week).Participants (n = 1809) reported on and submitted photos of their most used device and liquid. Participants were categorized into flavor groups of high prevalence in our sample and in prior literature: sweet, menthol/mint, or tobacco.Participants using liquids without nicotine or flavors other than sweet, menthol/mint, or tobacco were excluded (n = 320). Data were analyzed crosssectionally. Chi-square and linear regression (n = 1489) were used to examine device and liquid characteristics by flavor.Results: Sweet flavors were most common (n = 1135; 76.2%), followed by menthol/mint (n = 214, 14.4%) and tobacco (n = 140, 9.4%). Sweet flavors were less common among participants using reusable devices with disposable pods/cartridges (nicotine salt) than those using other device-liquid groupings (5.2% vs 86.5-93.9%; p < 0.001). Sweet flavors were less common among those using ENDS for non-flavor reasons vs the flavor (73.5% vs 90.4%; p < 0.001). Sweet flavors correlated with lower nicotine concentrations, higher wattages, and lower ages of ENDS first use (p < 0.001). Conclusions: Regulatory agencies must consider how regulations on device and liquid characteristics may affect ENDS users' behaviors (e.g., limiting availability of sweet flavors may encourage use of non-sweet flavors and lower wattages).