E-cigarettes versus nicotine replacement treatment as harm reduction interventions for smokers who find quitting difficult: Randomised controlled trial.

Abstract

BACKGROUND AND AIMS: The majority of smokers accessing the current best treatments continue to smoke. We aimed to test if e-cigarettes (EC) compared with nicotine replacement treatment (NRT) can help such smokers reduce smoking. DESIGN: Randomised controlled trial of EC (n=68) vs NRT (n=67) with 6-month follow-up. SETTING: Stop smoking service in London, UK. PARTICIPANTS: 135 smokers (median age=40, 51% males) previously unable to stop smoking with conventional treatments. INTERVENTIONS: Participants received either NRT of their choice (8 week supply), or an EC starter pack and instructions to purchase further e-liquids of strength and flavours of their choice themselves. Products were accompanied by minimal behavioural support. MEASUREMENTS: Participants who reported that they stopped smoking or reduced their daily cigarette consumption by at least 50% at six-month follow-up were invited to provide a carbon monoxide (CO) reading. The primary outcome was biochemically validated reduction in smoke intake of at least 50% at 6 months and the main secondary outcome was sustained validated abstinence at 6 months. Drop-outs were included as 'non-reducers'. FINDINGS: Validated smoking reduction (including cessation) was achieved by 26.5% vs 6.0% of participants in the EC and NRT study arms, respectively (relative risk (RR)=4.4, p=0.005, 95% confidence interval (CI):1.6 to 12.4). Sustained validated abstinence rates at 6 months were 19.1% vs 3.0% (RR=6.4, p=0.01, 95%CI: 1.5 to 27.3). Product use was high and equal in both study arms initially, but at 6 months allocated product use was 47% in the EC arm vs 10% in the NRT arm (chi(1)=22.0, p<.001), respectively. Adverse events were minor and infrequent. CONCLUSIONS: In smokers unable to quit using conventional methods, e-cigarettes were more effective than nicotine replacement therapy in facilitating validated long-term smoking reduction and smoking cessation, when limited other support was provided.