e-Cigarettes Nearly Twice as Effective as Nicotine-Replacement Therapy for Smoking Cessation

Use of e-cigarettes is almost twice as effective as nicotine-replacement therapy to help individuals quit smoking, according to a new study in New England Journal of Medicine. While e-cigarettes lack long-term research to determine their safety, they are still expected to reduce health risks compared to combustible cigarette smoking.

The researchers studied 886 adults attending smoking cessation services in the United Kingdom. The participants were randomized with 447 individuals assigned to a nicotine replacement-group and 439 assigned to an e-cigarette group. Both groups received weekly behavioral support for a minimum of 4 weeks.

The National Health Service in the United Kingdom provides free stop-smoking services. Researchers conducted a 2-group, pragmatic, multicenter, individually randomized, controlled trial within 3 service sites from May 2015 to February 2018. Participants were recruited through the Health and Lifestyle Research Unit, Leicester and East Sussex services, and through social media. Individuals were excluded in the study if they were not using either of the 2 products, had a strong preference to use 1 over the other, or were pregnant or breastfeeding.

During trial visits, data were gathered on adverse reactions, such as nausea, sleep disturbance, and throat or mouth irritation, smoking status, expired carbon monoxide level, use of trial products, and respiratory symptoms including shortness of breath, wheezing, cough, and presence of phlegm. Participants also provided ratings of trial products and withdrawal symptoms.

The primary outcome was sustained abstinence for 1 year, which was biochemically validated during the final visit of the trial. Secondary outcomes included participant-reported treatment usage and respiratory symptoms. The 1-year abstinence rate was 18.0% in the e-cigarette group compared with 9.9% in the nicotine-replacement group. Researchers found that 80% of participants in the e-cigarette group were more likely to continue using their product at 1 year compared to 9.0% in the nicotine-replacement group.

Participants with abstinence at weeks 1 and 4 after their quit date in the e-cigarette group had a lesser urge to smoke than those in the nicotine-replacement group. During the first week of abstinence, individuals in the e-cigarette group also reported to be less irritable, restless, and were more able to concentrate than those in the nicotine-replacement group. Differences between groups regarding hunger and depression were similar. Participants in either group who were abstinent reported little withdrawal discomfort by the fourth week.

Throat and mouth irritation was reported by 65.3% of participants in the e-cigarette group and 51.2% in the nicotine-replacement group. No significant differences were found between groups for prevalence of wheezing or shortness of breath. Nausea was reported by 37.9% of individuals in the nicotine-replacement group and 31.3% in the e-cigarette group. The incidence of cough and phlegm production declined in both groups from the beginning to the end of the trial. However, participants who reported respiratory symptoms at the beginning of the trial had significantly less symptoms by the trial’s conclusion in the e-cigarette group than in the nicotine-replacement group.

Participants in the nicotine-replacement group were offered a choice of products including patches, gum, lozenges, nasal or mouth sprays, inhalers, mouth strips, or microtabs. They were encouraged to choose a combination of products. Most participants chose the patch along with a fast-acting oral product. They were also free to switch products at will.

Individuals in the e-cigarette group were given a starter pack, a 30 mL bottle of tobacco flavored e-liquid with a nicotine concentration of 18 mg per mL, and instructions on how to operate and refill the device. Participants were encouraged to experiment with different flavored e-liquids with varying concentrations of nicotine.

Both groups respectively agreed that e-cigarettes and nicotine-replacement products were less satisfying than combustible cigarettes. However, participants stated e-cigarettes still provided greater satisfaction and were more helpful for smoking cessation than nicotine-replacement products.

The trial was approved by the National Research Ethics Service. Researchers only viewed collective unblinded data for the purposes of data-monitoring assessment by the ethics committee. Data analysis were conducted with blinding to treatment assignments.

Reference

Hajek P, Phillips-Waller A, Dunja P, et al. A randomized trial of e-cigarettes versus nicotine-replacement therapy [published online February 14, 2019]. N Engl J Med. doi: 10.1056/NEJMoa1808779