“E-cigarettes more effective than patches to help quit smoking, says study,” The Guardian reports. A UK study has found that people who use the aids are 60% more likely to quit than those who try nicotine replacement therapy (NRT) patches or gum, or willpower alone.
This was a “real world” study that surveyed a representative sample of the English population about their smoking habits.
The results of this study, whilst interesting, should be viewed with caution, as there are numerous limitations. This includes the fact it was not a randomised controlled trial (RCT), which is the best way to assess the effectiveness of treatments.
It also relied on people reporting quitting, but they may not have actually done so; self-reporting is not the most reliable of methods.
Finally, it did not compare e-cigarettes against medications, such as champix (varenicline), and psychological interventions. This makes it unclear how e-cigarettes compare to these methods.
Current evidence suggests that getting professional help through the NHS stop smoking service is the most effective way to quit.
E-cigarettes, however, are growing increasingly popular, so policymakers may need to decide whether or not they should be used by NHS smoking cessation services.
Where did the story come from?
The study was carried out by researchers from University College London and was funded largely by Cancer Research UK and the Department of Health.
Funding was also received from Pfizer, GlaxoSmithKline and Johnson and Johnson – pharmaceutical companies that produce and sell NRT products.
The researchers say they received no funding from any e-cigarette manufacturers.
The study was published in the peer-reviewed journal Addiction.
It was covered fairly in most of the UK media, although little mention was made of the study’s limitations.
One of the authors, Professor Robert West, has complained that he has been misquoted by The Sun newspaper.
He has released a statement saying: “I was not calling for e-cigarettes to be made available on the NHS. All I said was that as and when an e-cigarette receives a medical license, it should be theoretically possible for them to be prescribed.”
What kind of research was this?
This was a cross-sectional survey of 5,863 adults in England, who had made at least one attempt to quit smoking in the previous 12 months, either using e-cigarettes, NRT bought over the counter or with willpower alone. Its aim was to assess the effectiveness of the three different approaches in helping people to quit.
Cross-sectional surveys look at all data at one specific point in time. They provide a useful snapshot of links between people’s health and their lifestyle, but they cannot see if one thing follows another.
The authors point out that e-cigarettes are increasingly popular. Two RCTs have suggested they can aid smoking cessation, but there are many factors that could influence their effectiveness in the real world, such as who chooses to use them.
They also say it's important to know how e-cigarettes compare with licenced NRT products bought over the counter as an aid to quitting.
What did the research involve?
The study involved a survey of 5,863 adult smokers between 2009 and 2014, who had attempted to quit smoking at least once, without the aid of prescription medication or professional support.
It is part of an ongoing Smoking Toolkit Study, which is designed to provide information about smoking prevalence and behaviour in England. In this study, a new sample of about 1,800 adults aged 16 and above are selected randomly each month and asked to complete a face-to-face computer assisted survey with a trained interviewer.
The sample discussed here comprised adults who had made at least one attempt to quit in the 12 months prior to their interview.
They included people who had used e-cigarettes, NRT bought over the counter and those who had not used any treatment or support.
The researchers excluded those who had used a combination of methods, a prescription stop-smoking medication or face-to-face professional support.
To find out about quitting rates, people were asked how long their most serious attempts lasted before they begun smoking again. Those that said they were still not smoking at the time of the interview were defined as “non-smokers”.
The researchers adjusted their results for potential confounders, including degree of nicotine dependence, age, sex and social grade. They used standard statistical techniques to analyse their results.
What were the basic results?
The study found that of the 5,863 eligible adults who had made an attempt to quit in the previous year:
- 464 (7.9%) had used e-cigarettes
- 1,922 (32.8%) had used NRT bought over the counter
- 3,477 (59.3%) had used no aid
Non-smoking was reported in:
- 93/464 (20%) of those using e-cigarettes
- 194/1,922 (10.1%) of those using NRT bought over the counter
- 535/3,477 (15.4%) of those who had used no aid
E-cigarette users were more likely to report smoking abstinence than either those who used NRT bought over the counter (adjusted odds ratio 1.63 (95% confidence interval 1.17 to 2.27) or those using no aid (adjusted odds ratio 1.61, 95% confidence interval 1.19 to 2.18).
How did the researchers interpret the results?
The researchers concluded that e-cigarettes may be an effective aid to smoking cessation and, given their popularity, substantially improve public health. They also point out that NRT products bought over the counter did not appear to give better results than not using any aid in this study.
This was a useful “real world” survey, which involved a large nationally representative sample of adults in England.
Researchers adjusted their results for a large number of potential confounders, including the degree of nicotine dependence and the time elapsed since participants’ attempt to quit begun.
However, as the authors point out, this was not an RCT, which is the best method of determining the effectiveness of treatments. This means that measured and unmeasured confounders could have affected the results.
Another important limitation is the study’s reliance on adults self-reporting whether they had quit.
This could make the results unreliable, especially since participants had to recall their smoking over the previous 12 months. The study would be more reliable had smoking abstinence been verified biochemically.
The results of this survey seem to agree with the conclusion of a recent report by Public Health England (the NHS body responsible for public health) into e-cigarettes:
"Electronic cigarettes, and other nicotine devices...offer vast potential health benefits, but maximising those benefits while minimising harms and risks to society requires appropriate regulation, careful monitoring, and risk management.
However, the opportunity to harness this potential into public health policy, complementing existing comprehensive tobacco control policies, should not be missed."