Growing the research evidence on e-cigarettes

The use of e-cigarettes has risen rapidly, with great potential to aid tobacco harm reduction, but also uncertainty over uptake and potential negative consequences. Professor Linda Bauld reviews the unanswered questions and need for further research.

Smoking rates continue to decline in the UK and many other developed countries. This is good news for the prevention of the 14 types of cancer linked to tobacco use.

At the same time, in recent years there’s been a steady increase in the number of people who use electronic cigarettes — battery operated devices that mimic the ‘hand to mouth’ action of smoking and in most cases contain nicotine, but far fewer of the harmful chemicals found in tobacco smoke. Recent estimates suggest there are around 2.6 million adults who use e-cigarettes in the UK. E-cigarettes are now the most popular aid to stopping smoking, outstripping use of licensed cessation aids like Nicotine Replacement Therapy. Children and teenagers are also experimenting with these devices, but in both adults and teens regular use is confined to those who currently smoke or recently stopped smoking.

There is some good evidence on trends in e-cigarette use in the UK and other countries but research gaps remain.

What has Cancer Research UK been doing?

Research to inform cancer prevention is important and for this reason CRUK has paid close attention to how the research and policy landscape on e-cigarettes is developing. We’d like to see more and better quality studies on e-cigarettes which is why we’ve driven some important activities to inform e-cigarette research. But more needs to be done.

In 2015 CRUK held two workshops which brought together researchers, funders and members of the public including e-cigarette users. These meetings generated useful discussions and informed a list of research themes and questions for studies to explore.

Along with Public Health England and the UK Centre for Tobacco and Alcohol Studies, CRUK has established the UK Electronic Cigarette Research Forum. This brings together academics conducting studies on e-cigarettes with policymakers and professionals from across the UK who are interested in this area. UKECRF members meet three times a year in London and the forum also has a monthly evidence briefing sent to members and a wider group of readers. This briefing summarises interesting studies published in the last month and ends with an accessible commentary highlighting the implications of new studies for policy and practice.

New CRUK funded studies

CRUK has also funded a range of important new studies on e-cigarettes through our Population Research Committee (PRC) and our Tobacco Advisory Group (TAG). For example:

Lynne Dawkins and colleagues from London South Bank University have a new PRC funded study. They aim to examine whether puffing patterns change when the nicotine concentration in e-liquid varies, and the implications of this for toxicant exposure amongst users.

Lion Shahab at University College London and colleagues have recently completed a TAG funded study examining exposure to nicotine and tobacco-related toxicants in long term users of nicotine-containing products that is now being prepared for publication.

Amanda Amos from Edinburgh University and team have a TAG funded qualitative study which looks at young adults’ understanding and experience of e-cigarettes. This is making good progress and has recruited smoking and non-smoking participants who have used and not used e-cigarettes with the aim of developing a more sophisticated understanding of the drivers of experimentation or regular use.

Laura Jones from the University of Birmingham has another TAG funded study examining parents’ perceptions and experienced of using e-cigarettes in the home when young children are present, and two other research teams supported by TAG are examining e-cigarette use amongst smokers accessing stop smoking services.

What else needs to be done?

These studies are just some examples of what CRUK has funded so far — other research on e-cigarettes is also underway, and funders such as the National Institutes for Health (NIH) in the USA and the National Institute for Health Research (NIHR) here in the UK have also been active in supporting some new research in this area.

Yet important gaps remain. In particular there needs to be more evidence on:

· Safety (particularly in the longer term)

· The effectiveness of e-cigarettes for smoking cessation

· The longer term impacts of use by young people

· How the changing policy context (such as the introduction of the European Tobacco Products Directive) will influence e-cigarette use

Different types of studies using different research designs can help examine these topics. It is likely that larger studies in particular may fall into two categories.

First, there needs be longitudinal research that looks at trajectories of e-cigarette uptake amongst young people and adults. Many recent media headlines on e-cigarettes are drawn from data in cross-sectional studies (often surveys). These types of studies are useful for providing a ‘snapshot’ of what is happening in the population, but can’t determine causality. Only by following up the same groups of people over time can there be understanding of the relationship between e-cigarette use and smoking and look at what influences both using and stopping using e-cigarettes.

There also needs to be randomised controlled trials, particularly of e-cigarettes for smoking cessation. A recent Cochrane review identified only two of these that had been completed, both using now obsolete devices. More trials are underway in the UK and elsewhere but these are still relatively few in number. Only through well conducted trials can there be an assessment of how useful e-cigarettes are to help people move away from tobacco, particularly amongst priority groups where smoking rates are highest.

How can you help fill the gaps?

If you’re interested in e-cigarette research, CRUK would like to hear from you. There are two main routes for supporting studies in this area.

1. The Population Research Committee oversees several response-mode funding streams including programme, project and fellowship awards. The remit spans epidemiological, behavioural and methodological research (including trials), relating to prevention, screening, and early diagnosis of cancer.

2. The Tobacco Advisory Group funds project grants relating to specific policy areas including: monitoring impact of policy and practice changes; promoting best practice in smoking cessation, tobacco control and mass media; fiscal measures; retail regulation and the sales environment; health inequalities.

Applications are currently open for both of these awards.

The deadline for applications to the Population Research Committee is 27 May and for the Tobacco Advisory Group there is an outline application deadline of 20 June.

An important first step is to speak to colleagues at CRUK about your idea, and they can advise on where your research fits. If it is not relevant to CRUK, they may be able to recommend other funders. The best approach is often to develop a one page outline that can form the basis for discussion and send this on to the office.

Contact Lucy Davies by email lucy.davies@cancer.org.uk or phone 020 3469 8824 for applications to the Population Research Committee.

For applications to the Tobacco Advisory Group email Rebecca Wise Rebecca.wise@cancer.org.uk or phone 020 3469 8164.

In the meantime, if you are interested in joining the UK Electronic Cigarette Research Forum or simply receiving the monthly UKECRF evidence bulletin, contact us at tobaccocontrol@cancer.org.uk