Changes in preferred e-cigarette flavor, nicotine concentration, wattage and air valve settings and cigarette...

To characterize changes in preferred e-cigarette (EC) flavor, nicotine concentration, wattage and air valve openness over 12 weeks among adults who smoke and are attempting to switch to ECs, and examine whether these changes are associated with cigarettes smoked per day (CPD).

Secondary analysis of two arms of a three-arm randomized controlled trial (NCT03113136).

Two Midwestern United States cities.

265 adults uninterested in quitting smoking (38% male, 62% female, mean age 40.0 years, 83% white, mean 17 CPD), randomized to lower-wattage EC (n = 132) or higher-wattage EC (n = 133).

Preferred EC flavor (tobacco/tobacco blend, menthol, fruit/sweet), nicotine concentration, wattage, air valve openness (higher-wattage EC only) and CPD were assessed at baseline, 1-week, 4-week, 8-week and 12-week follow-ups.

Over 12 weeks, mean CPD decreased by approximately 10 cigarettes, from 16.7 to 6.6 in the lower-wattage group and from 17.4 to 7.0 in the higher-wattage group. Most participants preferred fruit/sweet flavors (58.2% at week 12). Throughout the study, participants preferred nicotine concentrations of 12 mg/ml in the lower-wattage group and 6 mg/ml in the higher-wattage group. Preferred nicotine concentrations generally decreased from baseline to week 12 for both groups, though the decrease was statistically significant only in the lower-wattage group. In the higher-wattage group, preferred wattage and air valve openness generally increased from baseline to week 12, with a statistically significant increase observed only for wattage from baseline to week 8 (23.22 W to 27.07 W). In the lower-wattage group, preferred EC settings were not associated with CPD at follow-ups. In the higher-wattage group, menthol flavor preference (vs. tobacco) and higher nicotine concentrations were associated with CPD reductions at follow-ups.

Among adults who smoke cigarettes and are switching to e-cigarettes, preferences for e-cigarette settings (flavor, nicotine concentration, wattage and air valve openness) did not change substantially over the first 12 weeks of use. Flavors and nicotine concentration options may support smoking reduction in adults who transition to e-cigarettes.