Electronic cigarettes (e-cigarettes) were first introduced in 2004. Ever since their introduction, they have been very popular among smokers attempting to quit smoking. These battery operated devices release nicotine vapours for inhalation. They replicate the behavioural and sensory experiences of smoking; which is one of the primary reasons for smokers to try them.
Prior research on the subject suggested that e-cigarettes were as effective as nicotine replacement therapy (NRT). The toxins detected in e-cigarettes are comparable to those in NRT and are significantly lower than in cigarette smoke. The Lancet research aimed to study the effectiveness of e-cigarettes and compare it with Nicotine patches and placebo e-cigarettes (those that do not contain nicotine) in smoking reduction, tobacco dependence and supporting withdrawal symptoms.
This article summarizes the findings of The Lancet Research. The study was conducted in Auckland, New Zealand on 657 participants attempting to quit smoking. The study compared the effectiveness of e-cigarettes against nicotine patches and placebo e-cigarettes in helping smokers quit the habit.
Although e-cigarettes are very popular, there is limited evidence for its superiority over patches and placebo cigarettes in attaining the intended result. For this study, the hypothesis that e-cigarettes with nicotine cartridges are more effective than patches and placebo e-cigarettes in helping smokers quit smoking was assumed.
The Lancelot Research was performed in Auckland, New Zealand, between September 2011 and July 2013 on 657 randomised smokers. The selection criteria for the participants was:
- aged over 18 years
- use of over 10 cigarettes everyday for over a year
- intention to quit smoking
- consented to being part of the trial
- had no medical conditions and were not on any cessation drugs
The participants were randomized into three parallel groups, one for e-cigarettes, the second for nicotine patches and the third for placebo e-cigarettes in a 4:4:1 ratio using computerized block randomization, block size nine, and stratification by ethnicity, sex and their nicotine dependence data. E-cigarettes (with 16mg nicotine), nicotine patches (21mg patch) and placebo e-cigarettes (no nicotine) were supplied to the participants of respective test groups from a week before the day they intended to quit the habit, till 12 weeks after the said date.
Prior to the test, the e-cigarettes that were to be used for the trials were subjected to analysis. It was observed that 300 puffs from one e-cigarette cartridge delivered the equivalent nicotine of one to five tobacco cigarettes. Of the first 20 participants tested for e-cigarettes, four succesfully completed the test. The blood plasma nicotine levels of these four participants who had used e-cigarettes for at least one week, were sampled at regular intervals for a duration of 1 hour. It was observed that the concentration was highest at 10 minutes following the usage of product. Based on these results, nicotine patches of 21mg/day were selected for the test group assigned to patches for the test. In the placebo cigarette group, the e-cigarettes used cartridges that had zero nicotine content, but were marked with labels masked to nicotine content.
Of the 657 participants, 289 received e-cigarettes, 295 patches and 73 placebo cigarettes. The participants were also provided limited behavioural support through voluntary telephone counseling. The effectiveness of these methods in causing abstinence was tested after 6 months, through exhaled breath carbon monoxide measurements. The primary outcome tested was total abstinence from smoking during the entire follow-up period. The tests were performed at 6 months after the quit day.
Secondary assessments were also conducted to collect data on no smoking in the last 7 days, number of cigarettes used per day, time to relapse, number of patches and cartridges used, other treatments and any adverse side-effects of reported incidences of withdrawal symptoms at 1, 3 and 6 months after the quit day .
Results of the trials:
The baseline characteristics of all three test groups were evenly balanced out. Statistical analysis of the results revealed an absolute difference of 10% in the quit rates between the e-cigarette group and the patch group, and a 15% difference between the e-cigarette group and placebo cigarette group. The results showed highest continuous abstinence rates at 6 months for the nicotine e-cigarettes group at 7.3%. However the abstinence results were lower than expected and the margin of difference was small. So the researchers couldn’t effectively conclude the superiority of nicotine e-cigarettes over patches. The 7-day point prevalence abstinence was more significant, as there was a marked difference in the results obtained for either method.
As part of the analysis, quit rates, relative risks and absolute risks for all groups were also analysed. The changes from baseline were adjusted in the results. The tests also compared results for sub-groups; men vs women and ethnic groups and recorded the observations. There were no significant differences in the test data between different sub-groups. The quit rates though initially high, showed a consequent decrease across all the groups. The time to relapse was approximately 50 days in most cases. The relapse time was considerably longer in the nicotine e-cigarette group, than in the case of the patch group or the placebo cigarette group.
57% of the nicotine e-cigarette group was able to cut down on their daily cigarette consumption by at least half by the end of the trial period. This outcome was higher than in the other two groups. Among the quitters, 8 out of 21 continued to use nicotine e-cigarettes at 6 months; and 63 of the 220 non-quitters also continued their use of e-cigarettes. There was limited usage of other cessation methods other than the test products in all three groups.
Majority of the participants using both nicotine e-cigarettes and placebo (no nicotine) e-cigarettes chose to recommend either products to smokers who were looking to quit and enjoyed the attributes that were similar to tobacco cigarettes.
The Lancet study was limited in many ways. The effect size and estimates of abstinence were optimistically calculated, allowing little adjustment for differences. Participants on patches were less enthusiastic to follow up and the withdrawal rates were higher in this group. The effectiveness of the cartridges were less than optimal, and this would also affect the end results.
Over the course of the trial and observation of results, e-cigarettes were found to be reasonably effective at helping smokers quit. The conclusion however is that the findings of the research do not reveal any significant differences in the effectiveness of e-cigarettes over nicotine patches in smoking cessation. It also reported that short term e-cigarette usage is associated with low risk, as there were no significant adverse events reported. Further the study also suggests nicotine e-cigarettes have potential as they were widely accepted by participants. Hence these should be explored further as an option to improve population health, as opposed to regular tobacco cigarettes.