E-cigarettes are nearly twice as effective as nicotine-replacement therapy at helping smokers to quit cigarettes, according to a new randomised trial.

The findings, published in the New England Journal of Medicine, showed the abstinence rate at one-year was 18% in the e-cigarette group compared to 9.9% in the nicotine-replacement group, with both groups receiving behavioural support.

Researchers from Queen Mary University of London believe the findings will make stop smoking services more likely to include e-cigarettes among their treatment options, and health professionals more comfortable in recommending e-cigarettes as a stop-smoking intervention.

Lead researcher Professor Peter Hajek said: “Although a large number of smokers report that they have quit smoking successfully with the help of e-cigarettes, health professionals have been reluctant to recommend their use because of the lack of clear evidence from randomised controlled trials. This is now likely to change.”

Public Health England (PHE) welcomed the “landmark research”, with Tobacco Control Lead Martin Dockrell saying that all stop smoking services should welcome smokers who want to quit with the help of an e-cigarette.

PHE has called for e-cigarettes to be made available to NHS patients, noting that research estimates that while not risk-free, vaping is at least 95% less harmful than smoking.

Last month the Government responded positively to recommendations made in a parliamentary report on e-cigarettes calling for a more risk-proportionate approach to the regulation of e-cigarettes, reaffirming its commitment to look at where it can sensibly deregulate without harming public health after the UK leave the European Union.

Long-term safety concerns

However, in an accompanying editorial Boston University researchers caution that the new evidence of the effectiveness of e-cigarettes in assisting with smoking cessation must be balanced against their short-term and long-term safety.

“With regard to the former, the data from Hajek et al are reassuring: the e-cigarette group had greater declines in the incidence of cough and phlegm than the nicotine-replacement group, no excess wheezing or dyspnea, and only a small incidence of oropharyngeal irritation,” Drs Belinda Borrelli and George O’Connor wrote.

However, they highlight that a key finding is that among participants with sustained abstinence at one-year, 80% in the e-cigarette group were still using e-cigarettes, whereas only 9% in the nicotine-replacement group were still using nicotine replacement.

They say this differential pattern of long-term use raises concerns about the health consequences of long-term e-cigarette use, noting that e-cigarette vapor contains may toxins and exerts potentially adverse biologic effects on human cells in vitro or in animal models, although toxin levels and biologic effects are generally lower than those of tobacco smoke.

“These findings argue against complacency in accepting the transition from tobacco smoking to indefinite e-cigarette use as a completely successful smoking-cessation outcome.”

“Use of e-cigarettes should be monitored by health care providers, like other pharmacologic smoking cessation treatments,” Drs Borrelli and O’Connor suggested.

First trial of modern e-cigarettes

The multicentre trial is the first to test the efficacy of modern e-cigarettes in helping smokers quit, with 886 people attending NHS stop smoking services randomised to either a second-generation refillable e-cigarette or a nicotine replacement treatment of their choice (including patches, gum, lozenges, sprays, inhalers or a combination).

The trial showed a stronger effect of e-cigarettes than previous trials, which the researchers suggest could be due to the inclusion of smokers seeking help in quitting, the provision of face-to-face support and the use of refillable e-cigarettes with free choice of e-liquids.

“The findings are likely to be valid for dependent smokers who seek help but may not be generalizable to smokers who are less dependent or who try e-cigarettes for reasons other than quitting smoking. In addition, they may not be generalizable to less effective first-generation e-cigarettes,” they said.