An exploration of flavours in studies of e‐cigarettes for smoking cessation: secondary analyses of a systematic review with meta‐analyses

Abstract

AimsTo estimate associations between e-cigarette flavour and smoking cessation and study product use at 6 months or longer. MethodsSecondary analysis of data from a living systematic review, with meta-analyses and narrative synthesis, incorporating data up to Jan 2022. Included studies provided people who smoked combustible cigarettes with nicotine e-cigarettes for the purpose of smoking cessation, compared with no treatment or other stop smoking interventions. Measurements included smoking cessation and study product use at 6 months or longer reported as risk ratios (RR) with 95% confidence intervals (CI); flavour use at any time points. ResultsWe included 16 studies (n=10,336); 14 contributed to subgroup analyses and 10 provided participants with a choice of e-cigarette flavour. We judged nine, five and two studies at high, low, and unclear risk of bias, respectively. Subgroup analyses showed no clear associations between flavour and cessation or product use. In all but one analysis tests for subgroup differences resulted in I 2 values between 0% and 35%. In the comparison between nicotine e-cigarettes and nicotine replacement therapy (NRT) (I 2 =65.2% for subgroup differences), studies offering tobacco flavour e-cigarettes showed evidence of a greater proportion of participants still using at six-months or longer (RR=3.81; 95% CI=1.45 to 10.05; 3 studies; n=1181; I 2 =84%), whereas there was little evidence for greater 6-month use when

Randomized trial assessing the effect of the JUUL system on switching away from cigarettes and smoking reduction among U.S. adults who smoke cigarettes.

“…There has been considerable debate regarding the role of ENDS flavors in facilitating switching away from cigarettes (Farsalinos et al, 2013;Ward-Peterson & Maziak, 2019). Some observational studies suggest that participants using ENDS in nontobacco flavors are more likely to switch than those using tobacco flavors (Chen, 2018;Friedman & Xu, 2020;Gendall & Hoek, 2021;Glasser et al, 2020;Gravely et al, 2020;Jones et al, 2019;Li et al, 2021;Mok et al, 2023), and that adults who smoke cigarettes often transition from tobacco to nontobacco flavors as they switch (Du et al, 2020;Russell et al, 2018), whereas other studies have not found significant associations between use of flavored ENDS and switching or quit attempts (Kasza, Edwards, Gravely, et al, 2021;Liber et al, 2023;Lindson et al, 2023;Schneller et al, 2019). U.S. adults who smoke and purchased JUUL products predominantly used nontobacco flavors, but evidence on the association of flavors and switching is mixed (Goldenson et al, 2021;Russell et al, 2019aRussell et al, , 2019b.…”