Cessation of smoking in people attending UK emergency departments: the COSTED RCT with economic and process evaluation.

Background: The emergency department represents a potentially valuable opportunity to support smoking cessation. Evidence is lacking around the use of e-cigarettes in opportunistic settings like the emergency department.

Objective: To undertake a randomised controlled trial in people who smoke attending United Kingdom emergency departments, testing a brief intervention which included provision of an e-cigarette versus signposting to smoking cessation services, assessing smoking abstinence.

Design: A two-arm pragmatic, multicentre, parallel-group, individually randomised, controlled superiority trial with an internal pilot, economic evaluation and mixed-methods process evaluation.

Setting: Six emergency departments across England and Scotland.

Participants: Adults who smoked daily, who were attending the emergency department for medical treatment or accompanying someone attending for medical treatment, were invited to participate. People were excluded if they had an expired carbon monoxide of < 8 parts per million, required immediate medical treatment, were in police custody, had a known allergy to nicotine, were daily e-cigarette users, were considered not to have capacity to consent or had already taken part in the trial.

Intervention: Brief stop smoking advice, e-cigarette starter kit and referral to stop smoking services.

Main Outcome Measures: The primary outcome was biochemically validated sustained abstinence at 6 months. Those lost to follow-up, or not providing biochemical verification, were considered not to be abstinent. Secondary outcomes were: self-reported 7-day smoking abstinence, number of quit attempts, number of cigarettes per day, nicotine dependence and incidence of self-reported dry cough or mouth or throat irritation.

Results: At 6 months, of 972 participants randomised, biochemically verified smoking abstinence was 7.2% in the intervention group and 4.1% in the control group (percentage difference = 3.3%) (95% confidence interval 0.3 to 6.3;  = 0.032) [relative risk 1.76 (95% confidence interval 1.03 to 3.01)]. Self-reported 7-day abstinence at 6 months was 23.3% in the intervention group and 12.9% in the control group (percentage difference = 10.6%) (95% confidence interval 5.86 to 15.41;  < 0.001) [relative risk 1.80 (95% confidence interval 1.36 to 2.38)]. Daily e-cigarette use was 39.4% in the intervention group and 17.5% in the control group at 6 months. No serious adverse events related to taking part in the trial were reported. The economic evaluation found the intervention was likely to be cost-effective, judged by the National Institute for Health and Care Excellence threshold. The process evaluation found the intervention to be acceptable to both staff delivering it and participants receiving it. The brief nature of the intervention was highly adaptable to context, and interviews demonstrated how the intervention supported different pathways towards cessation.

Limitations: The inability to blind participants or researchers, the relatively low level of biochemical verification due to the nature of the population recruited and the fact that those in the control group did not receive usual care.

Conclusions: An opportunistic smoking cessation intervention comprising brief advice, an e-cigarette starter kit and referral to stop smoking services is effective for sustained smoking abstinence with few reported adverse events.

Future Work: Future work will include testing other behaviour change interventions in the emergency department and adapting the Cessation of Smoking Trial in the emergency department intervention for other settings.

Funding: This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR129438.