DUO (Dual Users Observational Study)
Research type
Research Study
Full title
Cohort follow-up study of dual users of e-cigarettes and conventional cigarettes.
IRAS ID
181666
Contact name
Peter Hajek
Contact email
Sponsor organisation
Queen Mary, University of London
Duration of Study in the UK
2 years, 6 months, 2 days
Research summary
Most smokers who use electronic cigarettes (EC) do so because they are worried about the health risks of smoking. Some stop smoking, but the majority become ‘dual users’ who use both EC and normal cigarettes at least for a time. They typically reduce their smoke intake, but the health benefits of this are unclear.
It is not known whether dual use helps or prevents smoking cessation and what proportion of dual users manage to stop smoking altogether, how many stop EC use and after what length of time, whether there are patterns in switching between different types and strengths of EC products and how this affects stopping smoking, and whether dual users are interested in stop smoking support. It is also not known what proportion of nicotine that dual users consume comes from smoking and from vaping and whether this changes over time. No longitudinal studies of dual users have been conducted so far.
In addition to this, it is not known what proportion of dual users are interested in receiving assistance to help them stop smoking altogether; and what effects such assistance has. Nicotine replacement treatments (NRT) are unlikely to be attractive and useful to dual users because they are already using NRT in the form of EC; and they have decided to use EC rather than NRT products. Varenicline (Champix) is a more hopeful approach, but it is not known whether dual users would be interested in this option and what impact such treatment would have on smoking cessation and smoking reduction.
This study will provide new and potentially important information by following up a group of dual users over six months in the first instance with the aim to monitor naturally occurring changes in their smoking, vaping and nicotine intake; to assess their interest in smoking cessation treatment and their reactions to it; and to generate information needed to inform future public health policies and practical advice health professionals may provide to dual users.This study followed up 204 people who used both e-cigarettes and smoked (dual-users), for a period of 6 years. The aim of the study was to look at the ‘natural history’ of smoking and vaping and whether or not dual-users had an interest in using varenicline to stop-smoking and the outcome of this treatment on quitting. Participants taking part were mostly male (70%), white British (92%) and ages ranged from 22 years to 40 (average age was 28 years old).
Varenicline interest and outcomes:
80 participants (39%) opted to use varenicline to help them stop-smoking. At 6 months, those using varenicline were more likely to report they had not smoked in the last 3 months, compared to those who did not use varenicline. By 12 months, those using varenicline were more likely to report they had not smoked in the last 9 months compared to those not using varenicline.Follow up of vaping and smoking:
Over the course of the study the number of participants responding to the questionnaire decreased from 71% at 1 year to 8.8% at 6 years. This provides important information about how many people can be expected to remain in long-term studies of this type which provide no financial or other benefits and rely exclusively on participants’ interest and goodwill.
Because of the low response rates later on, we only looked at the data in the first 3 years where over 40% of participants completed the questionnaire. The number of participants ‘dual-using’ reduced over time. Rates of only vaping increased over time, whereas only smoking increased over time initially, but then decreased. Ratings of enjoyment of smoking and vaping remained stable over time.REC name
West Midlands - Solihull Research Ethics Committee
REC reference
15/WM/0334
Date of REC Opinion
28 Sep 2015
REC opinion
Further Information Favourable Opinion