September 15, 2023
A comprehensive new Cochrane analysis has found that nicotine e-cigarettes and the medicines cytisine and varenicline are the most effective options currently available for helping smokers quit long-term, going at least six months without smoking.
This is closely followed by using two forms of nicotine replacement therapy at the same time, such as a nicotine patch alongside gum, lozenges or nasal sprays.
The research was conducted by a team from the Nuffield Department of Primary Care Health Sciences at the University of Oxford with colleagues from the University of Leicester.
The study, published in the Cochrane Database of Systematic Reviews, compared the results for different stop-smoking aids that have been used in over 300 clinical trials involving more than 150,000 people.
The researchers used a statistical technique to combine data from the studies into a single analysis called ‘component network meta-analysis’ (CNMA). This meant they could compare smoking cessation methods against each other, using both direct comparisons within trials and indirect comparisons across trials, providing a comprehensive view of the relative effectiveness of each method.
Emphasising the potential impact of the findings, Dr Nicola Lindson, lead author and a senior researcher and lecturer based within Oxford’s Nuffield Department of Primary Care Health Sciences, said:
“Our research dives deep into the world of smoking cessation. By pulling together data from hundreds of studies and over 150,000 people, we can see that when people use the medicines licenced for quitting smoking or nicotine e-cigarettes, they are more likely to quit than if they do not use these aids.
“We have also shown that nicotine e-cigarettes, cytisine, and varenicline appear to help more people quit than other products used to stop smoking.”
E-cigarettes were found to help around 14 smokers per 100 quit long-term, compared to 6 in 100 trying to quit without any of the stop-smoking aids studied.
The smoking cessation medicines varenicline and cytisine were similarly effective. However, varenicline is not currently available in Europe, South America, Japan, and parts of North America due to a manufacturing problem. Cytisine is not currently licensed or marketed in most countries outside of Central and Eastern Europe, meaning it is unavailable in most of the world, including the UK.
This leaves nicotine e-cigarettes and combination nicotine replacement therapies as the two most effective stop-smoking aids available to most people. These work better when people are also receiving behavioural support to quit.
Dr Jamie Hartmann-Boyce, co-author who was based at the University of Oxford during the research and is now assistant professor at the University of Massachusetts Amherst, said:
“Our findings provide clear evidence of the effectiveness of nicotine e-cigarettes and combination nicotine replacement therapies to help people quit smoking. The evidence also is clear on the benefits of medicines cytisine and varenicline, but these may be harder for some people to access at the moment.
“The best thing someone who smokes can do for their health is to quit smoking, and evidence shows that using varenicline, cytisine, or nicotine e-cigarettes in combination with behavioural support will give them the best chances of successfully doing so.”