Can electronic cigarettes can help people quit smoking?

Smoking is a significant global health problem. Many people who smoke want to quit, but find it difficult to succeed in the long term. One of the most effective and widely used strategies to help people to give up smoking is to combat the cravings associated with nicotine addiction by delivering nicotine through patches and chewing gum.

The use of electronic cigarettes

Electronic cigarettes have been around in some form for a number of years, but recently their popularity has increased significantly, and they have begun to look and feel less like conventional cigarettes. Unlike chewing gum and patches, they mimic the experience of cigarette smoking because they are hand-held and generate a smoke-like vapour when used.  This helps to recreate sensations similar to smoking without exposing users or other people to the smoke from conventional cigarettes, and can be used to provide people who smoke with nicotine.

Research led by Oxford researchers

A team of researchers have updated a Cochrane Review that compares the effects of electronic cigarettes with other ways of delivering nicotine – such as patches and chewing gum – or with dummy electronic cigarettes that do not contain nicotine or no treatment. This updated review now includes 50 studies, an increase of 35 studies since it was last published in 2016. Twenty-four of these are uncontrolled studies, but their results support the data from the randomised controlled trials.

The lead author of this updated Cochrane Review, Jamie Hartmann-Boyce from the Cochrane Tobacco Addiction Group, hosted in the Nuffield Department of Primary Care Health Sciences, and Oxford's Centre for Evidence-Based Medicine, said, “The randomised evidence on smoking cessation has increased since the last version of the review and there is now evidence that electronic cigarettes with nicotine are likely to increase the chances of quitting successfully compared to nicotine gum or patches. Electronic cigarettes are an evolving technology. Modern electronic cigarette products have better nicotine delivery than the early devices that were tested in the trials we found, and more studies are needed to confirm whether quit rates are affected by the type of electronic cigarettes being used."

Reviewing the evidence

The researchers identified three studies, in 1498 people, that compared nicotine-containing electronic cigarettes with nicotine replacement therapy given as patches or gum.  The results showed that more people quit smoking if they used electronic cigarettes containing nicotine than if they used another form of nicotine replacement. If six people in 100 quit by using nicotine replacement therapy, 10 people in 100 would quit by using electronic cigarettes containing nicotine. This means an additional four people in 100 could potentially quit smoking with nicotine containing electronic cigarettes.

Similar results were seen in another three studies, involving 802 people, that compared nicotine-containing electronic cigarettes with electronic cigarettes that did not contain nicotine.

Evidence from four studies (2312 people) showed that more people who used nicotine-containing electronic cigarettes quit smoking than those who received only behavioural support or no support. If four people in 100 quit with no support, an additional six people in 100 might quit by using nicotine electronic cigarettes.