Study finds direct association between e-cigarette use and successful quitting

Electronic cigarettes are helping people who want to quit smoking to successfully kick the habit, according to a study on the population impact of e-cigarettes on quit rates. 

However, researchers found that e-cigarettes have not encouraged more smokers to attempt to stop smoking. Vaping, they found, has also led to a fall in the demand for prescription nicotine replacement therapy (NRT) in some cases. 

The researchers, writing in The BMJ
^[1]
(online, 13 September 2016), say: “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. Growth in the use of e-cigarettes for quitting has also been associated with a decline in use of NRT obtained on prescription, but has not clearly been associated with the use of other quitting support.” 

Researchers based their findings on an analysis of 1,200 smokers between 2006 and 2015 who were registered with the Smoking Toolkit Study. Data from NHS smoking cessation services in England for the same period were also used, which showed eight million smokers set quit dates. 

The researchers found that the success rate of quit attempts increased by 0.098% (95% confidence interval [CI] 0.064 to 0.132; P<0.001) and 0.058% (CI 0.038 to 0.078; P<0.001) for every 1% increase in prevalence of e-cigarette use by smokers and e-cigarette use during an attempt to quit, respectively. 

There was no clear evidence for an association between e-cigarette use and rate of quit attempts (β 0.025; 95% CI −0.035 to 0.085; P=0.41). But there was a negative association between e-cigarette use during a recent quit attempt and use of NRT obtained on prescription (β −0.098; CI −0.189 to −0.007; P=0.04). 

In an accompanying editorial in The BMJ
^[2]
(online, 13 September 2016), John Britton, director of the UK Centre for Tobacco and Alcohol Studies at the University of Nottingham, argues that e-cigarettes are just one of the factors that have influenced smokers to quit. 

Britton writes: “[It] remains unclear whether, or by how much, the availability of e-cigarettes has influenced quitting behaviour in the UK. 

“The key arbiter of this and other controversies over the role of e-cigarettes lies less in these data than in trends in smoking prevalence, which in 2015 fell by nearly one percentage point relative to 2014.” 

He argues that this “significant” year on year fall indicates that “something in UK tobacco control policy is working, and successful quitting through substitution with e-cigarettes is one likely major contributor”. 

“The challenge for public health is to embrace the potential of this new technology, and put it to full use,” says Britton. 

Action on Smoking and Health (ASH), a charity that campaigns to eliminate the harm caused by tobacco, describes the findings in The BMJ as “positive”. 

Deborah Arnott, chief executive of ASH, said in a statement that The BMJ research finds that the use of e-cigarettes in England is associated with a higher rate of successful quit attempts. 

“Taken together with continued year on year falls in smoking prevalence, this is a very positive finding that should reassure those concerned that smokers using e-cigarettes may lose their motivation to quit,” she writes. 

The research in The BMJ was published at the same time as the latest Cochrane review^[3]
 into e-cigarettes and smoking cessation. 

The review, published on 13 September 2016, concludes that e-cigarettes may help smokers to quit, confirming the findings of its earlier similar review. It also found that there were no serious side effects associated with e-cigarette use for up to two years.