UK trial: posted vape kit alone lifts six-month quit rate to 11.3%

Smokers posted a vape kit with no follow-up quit at 11.3% at six months, against 6.4% of those sent NHS support emails, a Queen Mary University of London trial reports. Four weeks of telephone follow-up raised the quit rate to 21.1%.

The NIHR-funded trial, published in NEJM Evidence, randomised 1,170 daily smokers who wanted to stop. It tested vaping without the multi-session behavioural support that most earlier e-cigarette trials bundled with the device.

Recruits were 48 years old on average, smoked an average of 19 cigarettes a day, and most had already tried stop-smoking treatments, according to the report. They were split into three groups of roughly equal size.

One group received automated emails from the NHS SmokeFree programme, with advice and daily motivational messages for 28 days. A second received a vape kit by post with a single explanation of how to use it. The third got the same kit, a call on quit day and then weekly calls for four weeks.

The kit held a battery and a tank, two 10 ml bottles of e-liquid at 18 mg/ml in tobacco and strawberry flavours, five spare coils and a guide to buying more supplies. It was expected to last around two weeks, after which participants bought their own supplies. The report identifies it as the One Kit E-Cigarette Kit, created by the British retailer UK Ecig Store.

Success meant continuous abstinence checked by exhaled carbon monoxide

The primary measure was continuous abstinence at six months, validated by carbon monoxide in exhaled breath. Participants lost to follow-up were counted as still smoking, which holds down quit rates in all three arms.

The authors calculate that participants given a vape alone were 1.76 times more likely to have quit at six months than the email group, and that telephone support increased those chances a further 1.87-fold over vaping alone. At one year the support advantage held, but the gap between kit-only and emails no longer reached statistical significance.

Email recipients took up vaping anyway, which complicates the headline gap

The report gives two figures for vaping in the email arm at six months. Its results table lists 21.9%; its text says nearly a quarter of that group, or 24.4%, were vaping. The available text does not reconcile the two, so the email group’s vaping share at six months is unconfirmed.

On either figure, 68% of email-group participants who had quit smoking were using an e-cigarette, which the authors say contaminates the main comparison.

Excluding email-group participants who vaped, that group’s quit rate would fall to 2.7%, four times lower than with vaping alone. The report also flags this analysis as a weakness: the 2.7% figure comes from excluding a large share of that group’s successes, so the fourfold gap may be overestimated.

Vaping also cut cigarette consumption among people who did not quit. At six months they smoked 6.4 fewer cigarettes a day in the email group, 8.2 fewer with vaping alone and 9.6 fewer with vaping plus support.

Phone calls worked by getting people to start vaping sooner

At four weeks, 74.2% of supported participants were still vaping, against 63.8% of the vape-only group, according to the authors. Among those who had quit smoking, the share still vaping was similar in both arms.

The authors read this as support encouraging early uptake of the device rather than making vaping itself more effective. The six-month quit rate with calls, 21.1%, remains below the 35.4% the authors attribute to the 2019 face-to-face trial; at one year the gap narrows to 16.8% against 18.0%. On the looser measure of no smoking in the previous seven days, the vape-only and vape-plus-support arms reached 27.5% and 32.6% at one year.

Among people who quit, vaping persisted: 83% were still vaping at one year. Nicotine strength fell over time, with the median in the vape-only arm dropping from 12 mg/ml at four weeks to 6 mg/ml at one year, and nearly 5% of respondents using a nicotine-free e-liquid at one year.

The authors acknowledge that long-term vaping probably carries respiratory and cardiovascular risks, though they say these are a fraction of the risks of smoking, and that continuing to vape can prevent a return to cigarettes.

Flavoured liquid and a trial setting limit how far the results travel

The supplied e-liquid was flavoured, so the findings do not transfer directly to markets that have banned flavours other than tobacco. Carbon monoxide testing detects smoking over the previous 24 hours only.

Participants, reassured by the trial setting, may also have taken up vaping more readily than ordinary smokers. In the UK, 52% of smokers still believe vaping is as harmful as, or more harmful than, smoking, according to the report.

The authors say the results support Britain’s Swap to Stop scheme, launched in 2023, under which local authorities provide free vape kits to people enrolled in stop-smoking services, whether or not they take part in multi-session support.

Retailers and stop-smoking commissioners face a supply question

The trial covered kit and coils for about two weeks, then left participants to buy their own. Quit rates therefore rest on users finding compatible refills and coils locally, and 83% of quitters were still vaping at one year.

For distributors, the hardware matters: a refillable tank with replaceable coils and 10 ml bottles at 18 mg/ml, not a sealed pod. For local authorities running Swap to Stop, the spread between posting a kit (11.3%) and adding four calls (21.1%) at six months sets the size of the gain from staffing a phone line.

Questions readers ask

How much does telephone support add to a vape kit for quitting smoking?

In the Queen Mary University of London trial, validated continuous abstinence at six months was 11.3% with a posted kit alone and 21.1% when four weeks of calls were added. At one year the rates were 9.0% and 16.8%, so the support advantage persisted but narrowed.

What was in the vape kit used in the NEJM Evidence trial?

The kit held a battery and tank, two 10 ml bottles of e-liquid at 18 mg/ml in tobacco and strawberry flavours, five spare coils and a guide to buying more supplies. It was expected to last around two weeks, after which participants bought their own.

Did people who quit smoking keep vaping after the trial?

At one year, 83% of participants who had quit smoking were still vaping, a share similar to the 2019 trial. Their nicotine strength declined, with the median in the vape-only arm falling from 12 mg/ml at four weeks to 6 mg/ml at one year.

What are the main limitations of the vape kit quit-smoking trial?

The carbon monoxide test detects smoking over the previous 24 hours only. The e-liquid was flavoured, limiting relevance to markets with flavour bans. Participants in a trial setting may also have taken up vaping more readily than ordinary smokers.