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Reference: N Engl J Med 2019 Jan 30 early online (level 2 [mid-level] evidence)
E-cigarettes are not an approved treatment for smoking cessation, but have nevertheless become popular among those trying to quit as well as those just looking to vape. Evidence to date is conflicting at best regarding the effectiveness of nicotine-containing e-cigarettes for tobacco cessation. A 2016 Cochrane found 2 randomized trials showing benefit and 1 trial with no difference. Trials evaluating e-cigarettes for smoking cessation typically have high drop-out rates (> 20%) and sustained cessation rates at 6-12 months in the 1-10% range.
A recent trial enrolled 886 adult smokers who were already attending free stop-smoking services provided by the UK National Health Service. Participants chose a quit date, and were randomized in a 1:1 ratio on their chosen quit date to receive their choice of nicotine replacement (NRT) products for up to 3 months or an e-cigarette starter pack including one bottle of nicotine 18-mg/ml nicotine e-liquid. Both groups also received the standard behavioral support as part of the stop-smoking services for at least 4 weeks during the trial. The primary outcome evaluated was 1 year of sustained tobacco abstinence, with 79% of participants completing the 52-week follow-up. Participants who reported abstinence or at least 50% reduction in smoking at 1 year were invited to return for biochemical verification (carbon monoxide reading). Participants who were lost to follow up or did not participate in the biochemical assessment were considered non-abstinent. Of the 886 total participants who were randomized, 18% in the e-cigarette group and 9.9% in the NRT group were abstinent at 1 year (RR 1.83; 95% CI 1.30-2.58; P<0.001, NNT 13).
The quit rates found in this study are significantly higher than those reported in other similar studies. Perhaps the degree of motivation of the participants, who were already attending stop-smoking services prior to enrollment, contributed to the higher success rate. Additionally, while high loss to follow-up (21% in this trial) is always a threat to the validity of a study, rates were on par with other trials studying smoking cessation. However, it is worth noting that evidence of efficacy for smoking cessation does not address the fact that toxins and carcinogens have been found in samples of the cartridges used in the devices, although traditional cigarettes have their share of toxins and carcinogens as well. Finally, it should also be noted that quit rates vary by ethnicity, with lower rates reported for African Americans compared to White or Hispanic Americans. This study did not report ethnicity data or include ethnicity in adjusted analyses, which limits interpretation of these results.
For more information, see the topic Nicotine replacement therapy for tobacco cessation in DynaMed Plus. DynaMed users click here.
DynaMed Plus EBM Focus Editorial Team
This EBM Focus was written by Sarah Dalrymple, MD, Faculty Development and Information Mastery Fellow and Clinical Instructor at the University of Virginia. Edited by Alan Ehrlich, MD, Executive Editor at DynaMed Plus and Associate Professor in Family Medicine at the University of Massachusetts Medical School and Katharine DeGeorge, MD, MS, Assistant Professor in Family Medicine at the University of Virginia and Clinical Editor at DynaMed Plus