The Effect of 12-Week e-Cigarette Use on Smoking Abstinence at 1 Year: The E3 Trial.

Background: The current evidence regarding the long-term efficacy of electronic cigarettes (e-cigarettes) for smoking cessation is unclear.

Objectives: The purpose of this study was to assess the efficacy, safety, and tolerability of nicotine and non-nicotine e-cigarettes for smoking cessation in the general population.

Methods: We randomized 376 adults who smoked ≥10 cigarettes/day and were motivated to quit at 17 Canadian sites to 12 weeks of nicotine (15 mg/mL) e-cigarettes (n = 128), non-nicotine e-cigarettes (n = 127), or no e-cigarettes (n = 121). All groups received individual counseling. The primary endpoint was point prevalence abstinence (7-day recall, biochemically validated using expired carbon monoxide) at 12 weeks. The 52-week follow-up results are reported here.

Results: Participants (mean age 52 ± 13 years; 47% female) smoked a mean of 21 ± 11 cigarettes/day at baseline. Compared to individual counseling alone, participants randomized to nicotine e-cigarettes plus counseling had higher rates of point prevalence (23.6% vs 9.9%; difference: 13.7%; 95% CI: 4.6%-22.8%) and continuous abstinence (3.1% vs 0.0%; difference: 3.1%; 95% CI: 0.1%-6.2%) and greater reductions in the number of cigarettes smoked (-9.5 ± 10.5 vs -5.6 ± 9.5; difference: -3.9; 95% CI: -6.5 to -1.4) at 52 weeks. Benefits were also observed among participants randomized to non-nicotine e-cigarettes plus counseling vs counseling alone. No differences in abstinence or reduction were found between nicotine and non-nicotine e-cigarettes.

Conclusions: Compared to individual counseling alone, short-term use of standardized nicotine and non-nicotine e-cigarettes plus counseling is efficacious at increasing smoking abstinence at 52 weeks.