A randomized trial of e-cigarettes versus nicotine-replacement therapy
There are several studies highlighting that nicotine-containing e-cigarettes are more effective than nicotine-free e-cigarettes in facilitating smoking cessation. However, previous studies directly comparing e-cigarettes and NRT have typically compared low-nicotine first-generation e-cigarettes and did not include any face-to-face contact.
This multicentre randomised controlled trial evaluated the 52-week efficacy of refillable second-generation e-cigarettes compared with NRT in facilitating smoking cessation in adults. Sustained abstinence was defined as a self-report of ≤5 cigarettes from two weeks after the target quit date, validated by expired carbon monoxide levels at 52-week follow-up. Secondary outcomes included abstinence at other timepoints, cigarette use in participants without sustained abstinence, respiratory symptoms, withdrawal symptoms and adverse reactions.
886 adults attending NHS stop-smoking services between May 2015 and February 2018 were randomly assigned to either an e-cigarette starter pack or an NRT of their choice. Participants in the e‑cigarette group were provided with a refillable second-generation e-cigarette and a bottle of nicotine e-liquid and were encouraged to experiment with e-liquids of different strengths and flavours. The NRT group could select products such as patches, gums, lozenges, nasal sprays, inhalers, mouth sprays and microtabs and were encouraged to combine products. Both groups received the same multisession behavioural support.
The study authors found that 52-week abstinence rates in the e-cigarette group were almost double that of the NRT group. Among the participants who were abstinent at 52 weeks, those randomised to e-cigarettes were more than eight times as likely to still be using their product. E-cigarettes caused more throat/mouth irritation and NRT caused more nausea. Greater decreases in the incidence of cough and excess phlegm were reported in the e-cigarette group, but there were no significant differences between groups for shortness of breath, wheeze and adverse events. E‑cigarettes were more effective in reducing tobacco withdrawal symptoms and were rated higher than NRTs by participants. Some participants did not achieve full abstinence, but those randomised to e-cigarettes were more likely to reduce their cigarette use than those using NRT.
Strengths of this study included: (1) participant autonomy in choice of e-liquids and NRT, (2) inclusion of behavioural support for both groups, (3) inclusion of many participants from multiple centres. Its limitations included: (1) inability to blind product assignment, (2) carbon monoxide validation only detects smoking in the last 24 hours; therefore, false negatives are a possibility.
The authors concluded that e-cigarettes are more effective for smoking cessation than NRT and may allow better tailoring of nicotine dose to individual needs.