The rise in the use of e-cigarettes in England has been associated with an improvement in the success of quit attempts, a study in the BMJ has found.

The researchers at University College, London used time series data on smoking cessation activity and the prevalence of e-cigarette use in England, while correcting for potential confounding variables, to provide a direct estimate of the impact of the rise of e-cigarette use on attempts to stop smoking.

Data for the study were sourced from quarterly reporting from the Smoking Toolkit Study. The study involves monthly surveys of representative samples of smokers in England aged 16 years or more.

The surveys include questions on quit attempts and on e-cigarette use.

Data from 170,490 individuals were collected. Statistics on the use of NHS stop smoking services were obtained from the NHS Information Centre.

The study found a positive association between increasing e-cigarette use and successful quit rates. Successful attempts increased by 0.098% (95% CI: 0.064-0.132%; P < 0.001) for every 1% increase in e-cigarette use. E-cigarette use in quit attempts was also positively associated with quit success. There was a 0.058% (95% CI: 0.038-0.078%; P < 0.001) increase in the success of attempts for every 1% increase in e-cigarette use during a quit attempt.

There was no association between e-cigarette use and the number of quit attempts, the use of prescription treatments in general to support quitting, use of over the counter nicotine replacement therapy (NRT), or in access to behavioural support to stop smoking.

There was a small negative association between e-cigarette use during a recent quit attempt and use of prescription-based NRT treatment.

The study authors conclude: ‘The increased prevalence of e-cigarettes in England does not appear to have been associated with a detectable change in attempts to stop smoking. However, the increase in e-cigarette use has been associated with an increase in success of quit attempts.’