Abstract
BACKGROUND
Over the past few years, a large number of smokers in the UK have stopped smoking with the help of e-cigarettes. So far, UK Stop Smoking Services (SSSs) have been reluctant to include e-cigarettes among their treatment options because data on their efficacy compared with the licensed medications are lacking.
OBJECTIVE
The objective was to compare the efficacy of refillable e-cigarettes and nicotine replacement therapy (NRT) products, when accompanied by weekly behavioural support.
DESIGN
A randomised controlled trial comparing e-cigarettes and NRT.
SETTING
Three sites that provide local SSSs.
PARTICIPANTS
The participants were 886 smokers seeking help to quit smoking, aged ≥ 18 years, not pregnant or breastfeeding, with no strong preference to use or not to use NRT or e-cigarettes in their quit attempt, and currently not using NRT or e-cigarettes. A total of 886 participants were randomised but two died during the study (one in each study arm) and were not included in the analysis.
INTERVENTIONS
The NRT arm (n = 446) received NRT of their choice (single or combination), provided for up to 12 weeks. The e-cigarette arm (n = 438) received an e-cigarette starter pack and were encouraged to buy addtional e-liquids and e-cigarette products of their choice. Both arms received the same standard behavioural support. Participants attended weekly sessions at their SSS and provided outcome data at 4 weeks. They were then followed up by telephone at 6 and 12 months. Participants reporting abstinence or at least 50% reduction in cigarette consumption at 12 months were invited to attend for carbon monoxide (CO) validation. Participants/researchers could not be blinded to the intervention.
MAIN OUTCOME MEASURES
The primary outcome was CO-validated sustained abstinence rates at 52 weeks. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. Secondary outcomes included abstinence at other time points, reduction in smoke intake, treatment adherence and ratings, elicited adverse reactions, and changes in self-reported respiratory health. A cost-efficacy analysis of the intervention was also conducted.
RESULTS
The 1-year quit rate was 9.9% in the NRT arm and 18.0% in the e-cigarette arm (risk ratio 1.83, 95% confidence interval 1.30 to 2.58; p < 0.001). The e-cigarette arm had significantly higher validated quit rates at all time points. Participants in the e-cigarette arm showed significantly better adherence and experienced fewer urges to smoke throughout the initial 4 weeks of their quit attempt than those in the NRT arm, and gave their allocated product more favourable ratings. They were also more likely to be still using their allocated product at 1 year (39.5% vs. 4.3%, χ2 = 161.4; p < 0.001). Participants assigned to e-cigarettes reported significantly less coughing and phlegm at 1 year than those assigned to NRT (controlling for smoking status). A detailed economic analysis confirmed that, because e-cigarettes incur lower NHS costs than NRT and generate a higher quit rate, e-cigarette use is more cost-effective.
LIMITATIONS
The results may not be generalisable to other types of smokers or settings, or to cartridge-based e-cigarettes.
CONCLUSIONS
Within the context of multisession treatment for smokers seeking help, e-cigarettes were significantly more effective than NRT. If SSSs provide e-cigarette starter packs, it is likely to boost their success rates and improve their cost-efficacy.
FUTURE WORK
The efficacy of e-cigarettes provided with different levels of support will show whether smokers should be encouraged to switch to vaping within support services or whether e-cigarettes can be recommended with less intensive or no support.
TRIAL REGISTRATION
Current Controlled Trials ISRCTN60477608.
FUNDING
This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 43. See the NIHR Journals Library website for further project information. The trial was supported by the Cancer Research UK Prevention Trials Unit (grant A16893).
Plain language summary
Alarge number of smokers in the UK have stopped smoking with the help of e-cigarettes, but it is not known if e-cigarettes are as helpful as stop smoking medications that are provided by the UK Stop Smoking Services (SSSs). This information is needed to decide whether or not SSSs should include e-cigarettes among their treatment options. A total of 886 smokers who were seeking help with quitting and did not mind whether they would use nicotine replacement therapy (NRT), such as nicotine patches, or e-cigarettes were recruited at three SSSs. The smokers were randomly allocated (by chance) to receive weekly behavioural support and either a NRT of their choice (a single NRT product or product combinations) (n = 447) or a starter pack of e-cigarettes (n = 439). The trial ran from May 2015 to February 2018. The participants were followed up for 1 year to see how many stopped smoking in each group. Smokers using e-cigarettes suffered less cigarette withdrawal discomfort early on and had higher quit rates at all time points. At 1 year, 10% of participants in the NRT trial arm had been abstinent for the whole year, compared with 18% in the e-cigarette arm; regarding abstinence for at least 6 months, the figures were 12% in the NRT arm and 21% in the e-cigarette arm. Of interest, coughs and phlegm production also reduced more in people quitting with e-cigarettes than those quitting with NRT. This supports previous reports suggesting that an ingredient in e-cigarettes (i.e. propylene glycol) may protect vapers from airborne infections. E-cigarette starter packs cost much less than NRT and so, if SSSs provide them, their use is likely to boost the success rates and reduce the costs of SSSs.
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