E-cigarettes show about the same rate of success in helping smokers quit as nicotine patches, according to the results of a trial that compared both methods against a placebo.
The findings were presented at the European Respiratory Society (ERS) Annual Congress in Barcelona, Spain, and were also published online in The Lancet. The researchers say theirs is only the second controlled study to evaluate the effectiveness of e-cigarettes but the first to compare them against nicotine patches.
E-cigarettes, or electronic cigarettes, are battery-powered devices that allow users to inhale doses of vaporized nicotine. Nicotine patches are transdermal patches that release nicotine into the body through the skin.
Lead investigator Chris Bullen, professor and director of the National Institute for Health Innovation at the University of Auckland in New Zealand, says:
"Our study establishes a critical benchmark for e-cigarette performance compared to nicotine patches and placebo e-cigarettes, but there is still so much that is unknown about the effectiveness and long-term effects of e-cigarettes."
The trial found that e-cigarettes and nicotine patches had comparable rates of success with few adverse events: roughly similar proportions of smokers were still not smoking 3 months after following a 13-week course using either e-cigarettes or nicotine patches.
However, the researchers caution that it is still too early to say where e-cigarettes fit into tobacco control and that more studies should be done to "establish their overall benefits and harms at both individual and population levels."
Prof. Bullen says:
"Given the increasing popularity of these devices in many countries, and the accompanying regulatory uncertainty and inconsistency, larger, longer-term trials are urgently needed to establish whether these devices might be able to fulfil their potential as effective and popular smoking cessation aids."
E-cigarettes versus nicotine patches
E-cigarettes were just as effective as nicotine patches in helping smokers quit.
For their study, the team used adverts in local newspapers to recruit 657 adult smokers (aged 18 and over) who wanted to quit.
They randomly assigned the volunteers to one of three treatment groups, in a 4:4:1 ratio, ensuring a balanced distribution of sex, ethnicity and nicotine dependence:
- The first group (289 volunteers) was given 13 weeks' supply of commercially available e-cigarettes, each containing about 16 mg of nicotine
- The second group (295 volunteers) received 13 weeks' supply of nicotine patches (21 mg patch, one daily)
- The third group (73 volunteers) received 13 weeks' supply of placebo e-cigarettes (containing no nicotine).
During the 13 treatment weeks and 3 months after (a total study period of 6 months), participants underwent breath tests to check whether they had managed to abstain from smoking.
At the end of the study period, the results showed that overall, 5.7% of participants (about 1 in 20) had managed to quit completely.
The results showed that the percentage of e-cigarette quitters was highest, at 7.3%, compared with 5.8% of the nicotine patches users, and 4.1% of the placebo e-cigarette users.
Quit rate too low for statical significance
The team notes that, unfortunately, the unexpectedly low rate of abstinence was not enough for the statistical analysis to show whether the differences among the groups are significant or not.
So although the numbers suggest the quitting rate was roughly 25% higher in the e-cigarette group than in the patches group, the researchers can confidently only say e-cigarettes are comparable to patches.
But they did not find any statistically significant differences among the adverse events reported by the volunteers in the two groups.
Relapsed e-cigarette users smoked less
Among the relapsers - that is, those who resumed smoking during the study period - the e-cigarette users smoked markedly fewer cigarettes than the other two groups.
Of the volunteers in the e-cigarette group, 57% had halved their daily cigarette use by the end of the 6 months, compared with only 41% in the nicotine patches group and 45% in the placebo group.
One month after their treatment ended, the volunteers were asked if they would recommend it to a friend.
About 9 out of 10 of the e-cigarette and placebo (i.e. e-cigarette with no nicotine) groups said they would, compared with only 56% of the patches group. These figures stayed much the same after 6 months.
More research needed
President of the European Respiratory Society, Professor Francesco Blasi, says the advent of e-cigarettes is causing much debate among health professionals, and the study takes us a step closer to understanding how effective they are in helping smokers quit.
However, he does caution that "we need more research on the positive or negative effects of these products."
He says although this study clearly shows people are very enthusiastic about these devices, we need to find out how safe they are, and we need long-term independent clinical trials and behavioural studies, as there is very little data:
"Until this strong scientific evidence exists, policymakers who are deciding how to regulate the devices should proceed with caution."
Another part of the debate surrounding electronic cigarettes is regulation. There is a view that if all nicotine-containing products were licensed, then smokers using them to cut down or quit smoking would be assured of a certain standard.
In the UK, all nicotine-containing products, such as electronic cigarettes, are to be regulated as medicines, in a move to make them safer and more effective in reducing the harms of smoking.
Research from 2012 revealed that e-cigarettes do cause lung damage.