Abstract
BACKGROUND: 'Ice' e-cigarette flavours-marketed as a combination of fruity/sweet and cooling flavours (eg, 'blueberry ice' or 'melon ice')-recently entered the US market. The prevalence and correlates of ice flavoured e-cigarette use in young adults are unknown. METHODS: This cross-sectional study of a Los Angeles, California, USA, cohort analysed data from the past 30-day e-cigarette (current) users (n=344; M (SD)=21.2 (0.4) years old) who completed web-based surveys from May-August 2020. The exposure variable was self-reported e-cigarette flavour used most often in the past month (menthol/mint, fruit/sweet or ice). Outcomes included self-reported combustible tobacco use, vaping dependence symptoms, frequency of use and device type used. RESULTS: Among current e-cigarette users, 48.8% reported using ice flavours most often, 33.7% predominately used fruit/sweet and 17.4% used menthol/mint. Using primarily ice-flavour was associated with reporting more past-30-day vaping days (vs menthol/mint: b=4.4, 95% CI (1 to 7.7); vs fruit/sweet: b=3.6, 95% CI (0.8 to 6.4)) and more episodes per vaping day versus fruit/sweet users (b=2.4, 95% CI (0.5 to 4.3)). Ice-flavour users were less likely than menthol/mint users to use JUUL/cartridge-based rechargeable (OR=0.1, 95% CI (0.03 to 0.45)) and more likely than sweet/fruit users to use disposable non-cartridge (OR=3.9, 95% CI (2.1 to 7.4)) devices than refillable/rechargeable tank/pen or other devices. Ice users had greater odds of past 30-day combustible tobacco use versus menthol/mint users (OR=2.7, 95% CI (1.3 to 5.7)) and vaping dependence symptoms than versus sweet/fruit users (OR=2.6, 95% CI (1.5 to 4.4)). CONCLUSION: Young adult use of ice flavoured e-cigarettes may be common and positively associated with combustible tobacco use, nicotine vaping frequency and dependence and use of disposable e-cigarette devices. Further study of the prevalence, determinants and health effects of ice flavoured e-cigarette use is warranted.