Rise in e-cigarettes linked to rise in smokers quitting, say researchers

Dr Bullen, a Professor of Public Health at the University’s School of Population Health, says this latest study raises an important question of relevance to New Zealand - if e-cigarettes are effective at helping to increase smoking cessation, why are some countries restricting their sale?

The US study, published today in the British Medical Journal (BMJ) is based on the largest representative sample of e-cigarette users to date, and provides a strong case that e-cigarettes have helped to increase smoking cessation at the population level.

Currently, the scientific community is divided over whether e-cigarettes are an aid to quitting smoking. Some suggest that e-cigarettes will have a positive impact on smoking rates by acting as a nicotine replacement therapy, while others argue that they could reduce the urgency to quit smoking.

A team of researchers, led by Professor Shu-Hong Zhu at the University of California, set out to examine whether the increase in use of e-cigarettes in the USA, was associated with a change in overall smoking cessation rate at the population level.

They base their findings on five population surveys dating from 2001 to 2015. E-cigarette users were identified from the most recent survey (2014-15) and smoking cessation rates were obtained from those who reported smoking cigarettes 12 months before the survey. Rates from this survey were then compared to four earlier surveys.

Of 161,054 respondents to the 2014-15 survey, 22,548 were current smokers and 2,136 recent quitters. Among them, 38.2 percent of current smokers and 49.3 percent of recent quitters had tried e-cigarettes.

The results show that e-cigarette users were more likely than non-users to make a quit attempt (65 percent v 40 percent) and more likely to succeed in quitting for at least three months (8.2 percent v 4.8 percent).

The study has two key findings. First, in 2014-15, e-cigarette users attempted to quit cigarette smoking and succeeded in quitting smoking at higher rates than non-users. Second, the overall smoking cessation rate in 2014-15 increased significantly from that of 2010-11.

In his accompanying BMJ editorial, Professor Bullen questions whether other tobacco control interventions operating at the same time may have been key triggers to the increase, but says Shu and colleagues “mount a convincing case for why the two most likely candidates - a large federal tobacco tax increase in 2009 and a nationwide mass media campaign - could not be stand-alone reasons for the change in cessation rates.”

Professor Bullen notes that while the research did not include a consideration of safety, there is a growing body of evidence that using e-cigarettes is far less harmful than continuing to smoke tobacco. “Policymakers in countries contemplating a more restrictive approach to the regulation of e-cigarettes should pause to consider if pursuing such a course of action is the right thing to do for population health,” he says.

Professor Bullen’s research group, the National Institute for Health Innovation, is undertaking several research studies that examine the role of e-cigarettes as aids to quitting smoking.

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