Medical | Sarah Dalrymple, MD| March 04, 2019
The EBM Focus series is a collection of concise summaries of clinical trials most likely to inform clinical practice, curated by the DynaMed Plus® editorial team. Read this EBM Focus about e-cigarettes for smoking cessation.
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 two randomized trials showing benefit and one 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.
For smokers highly motivated to quit, e-cigarettes might be a more effective option than traditional nicotine replacement therapy.
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 three 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 four weeks during the trial. The primary outcome evaluated was one 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 one 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 one year (relative risk 1.83; 95% CI 1.30-2.58; P<0.001, NNT 13). Suggesting that for smokers highly motivated to quit, e-cigarettes might be a more effective option than traditional nicotine replacement therapy.
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. 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.
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This EBM Focus was written by Sarah Dalrymple, MD, Faculty Development and Information Mastery Fellow and Clinical Instructor at the University of Virginia and 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.
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