Background
Smoking is a leading cause of preventable morbidity and mortality worldwide. In the words of the packaging: ‘Smoking Kills’. If we could persuade more people to give up, it follows that all our lives would be better.
Despite numerous public health campaigns, the availability of cessation aids, and the increasing social unacceptability of tobacco, a substantial proportion of the population continues to smoke. The emergency department (ED) presents a unique opportunity for intervention, as it often serves as the primary point of healthcare contact for many smokers — particularly those from lower socio-economic backgrounds who may not regularly visit their GP. This study, the Cessation of Smoking Trial in the Emergency Department (COSTED), aimed to evaluate the effectiveness of an ED-based smoking cessation intervention.
What kind of study is this?
The COSTED study is an randomised controlled trial (RCT). As any regular reader of the blog will know, this is the most reliable form of clinical trial for determining the efficacy of an intervention — although in this case, it was impossible to offer a placebo or blind the participants. RCTs minimise bias by randomly allocating participants to either intervention or control, ensuring that the two groups are comparable at the start of the study. This design aims for any outcome differences to be attributed to the intervention itself rather than to confounding factors.
In this study, participants who were smokers and presented to the ED were randomly assigned on a 1:1 basis to receive either a formal smoking cessation intervention or “standard care” consisting of brief smoking cessation advice.
Tell me about the patients.
Participants were recruited from six EDs in the UK National Health Service (NHS) over the first eight months of 2022. The trial included adults aged 18 and over who were current daily smokers of at least one cigarette per day with an expired carbon monoxide level of >8 parts per million.
There were a range of sensible exclusions, including patients requiring immediate treatment, those deemed unable to give informed consent, and those already using an e-cigarette daily. Importantly, recruitment was open to both patients in the ED and those accompanying them.
In total, 972 smokers were recruited to this trial. Their baseline characteristics are interesting. The majority were white, British men, who smoked on average fifteen cigarettes per day. Perhaps most startling to me — as a father of teenage boys — was their self-reported age when they started, which averaged out across the two groups at sixteen.
What was the intervention?
Patients in the intervention group (n=484) received an opportunistic smoking cessation intervention undertaken face-to-face in the ED by a dedicated smoking cessation advisor. The advisors were trained specifically for the role and were research nurses, research practitioners, ED nurses or healthcare assistants seconded to the trial. They received two-and-a-half days of training.
The intervention comprised of three elements:
- Brief (<15 minutes) smoking cessation advice
- Provision of an e-cigarette starter kit with brief (<15 minutes) advice on its use
- Formal referral to local smoking cessation services
The “standard care” group (n=488) were given details of local smoking cessation services via written material, but were not referred directly. This was done by a member of the research team, not an ED clinician.
For their time and trouble the participants were all offered a £30 shopping voucher. If they successfully gave up smoking, they were given a second £30 voucher as a bonus (they didn’t know about this until afterwards).
The intervention guidance can be viewed here.
What was the industry involvement in this study?
The trial used the DotPro e-cigarette starter kit, which is a ‘pod’ device manufactured by an independent manufacturer (Liberty Flights) with no financial connection to the tobacco industry. The DotPro was chosen based on in-depth patient and public consultation, considering ease of use, nicotine delivery, satisfaction, price and availability.
The DotPro kit was purchased at wholesale price and included eleven pods of 20mg/mL nicotine strength. Flavours included tobacco, berry, and menthol. Liberty Flight had no role in study design, data collection, data analysis, data interpretation or manuscript composition.
Funding for the trial came from the UK National Institute for Health and Care Research (NIHR).
What were the measured outcomes in this study?
The primary outcome of the COSTED trial was the achievement of smoking cessation at six months, which was self-reported by participants but also verified through carbon monoxide monitoring. If neither of these could not be obtained it was assumed that the participant was still smoking.
Secondary outcomes included:
- 7-day point-prevalence smoking status at 1 and 3 months post-randomisation
- Number of attempts to quit
- Time to relapse (if applicable)
- Number of cigarettes smoked per day
- Nicotine dependence
- Number of times using an e-cigarette per day
- Incidence of self-reported smoking-related symptoms, including dry cough and irritated mouth/throat
- Motivation to stop smoking
- Self-reported use of healthcare services in the last 6 months,
- Self-reported use of smoking cessation services in the last 6 months
- Quality of life (EQ-5D-5L)
What were the main results?
In total, 72% of the intervention group and 65% of the control group contributed data at the six month follow-up point. This is an impressively low attrition rate, given the group the researchers were working with.
The main findings of the trial were as follows: at six months, 7.2% of participants in the intervention group had given up smoking, compared to 4.1% in the control group. The absolute risk reduction is 3.1%, which gives us a number-needed-to-treat (NNT) of 32.
In plain language: for every 32 participants who received the trial intervention, one successfully gave up smoking.
The authors also expressed their results in terms of relative risk. Participants in the intervention group were 76% more likely (RR 1.76) to stop smoking. The word “more” here is emphasised because the overwhelming majority of participants in both groups did not stop smoking. The primary trial findings were statistically significant, with a p value of 0.038.
What are the main strengths of this trial?
This trial had a good number of participants, and included people from a diverse range of UK hospitals. They achieved the recruitment targets specified by their power calculation and the trial results meet standard thresholds for statistical significance. I can easily picture how I could take the researchers’ approach and apply it in my ED.
What are the key limitations to this trial?
The control group didn’t really get ‘”usual care.” They got much more than a leaflet suggesting they give up smoking and offering signposting to services. In order to check their eligibility and recruit them to the trial, they were asked extensive questions about their smoking habits and had carbon monoxide testing. When I was being taught chest examination (a “few” years ago) I was told that merely asking the patient if they smoke while listening to their breath sounds could be enough to plant a seed suggesting they give up. It is hard to imagine that an extended conversation would not have an effect.
Gathering carbon monoxide data to definitively prove cessation was difficult, and a significant proportion of patients were lost to follow-up. Again, given the group being studied, kudos must be given to the researchers for the numbers they did achieve. However, this does limit how much we can believe the findings. Some of the patients who claimed to have given up smoking, but did not present for carbon monoxide testing, may not have been telling the truth. This might be counter-balanced by the assumption made in the trial analysis that patients who were completely lost to follow-up had continued to smoke.
Discussion
It is hard to argue against this sort of intervention. There are no downsides for the participants — apart from the time the intervention takes — and every person we can encourage to give up smoking must be seen as a success.
We know that the population attending the ED may be amongst the hardest to reach with this sort of health advice, and having a ready-made cohort of potential participants is enticing. But this argument could be made for all sorts of health interventions. We could ask about (and measure) blood pressure and cholesterol levels, for example. We could screen for sexually transmitted diseases, as we have discussed before at St Emlyn’s. All of these could make a real difference to the public health of the population, but are our departments really set up for this?
We could co-locate a health screening facility next to every ED, but this seems rather against the current trend to redirect people away from emergency care. Would something like this not attract more patients to us?
Summary
The COSTED trial demonstrates that an ED-based smoking cessation intervention can significantly improve quit rates and reduce smoking intensity among participants. However, despite the obvious potential for an intervention like this, is there the organisational will (and money) to make this happen?
References
- Pope I, et al. Cessation of Smoking Trial in the Emergency Department (COSTED): a randomised controlled trial. Emerg Med J. 2024;41:276-282. doi:10.1136/emermed-2023-213824.
- Reid RD, et al. Smoking cessation in the emergency department: a systematic review of the literature. Nicotine Tob Res. 2015;17(6):710-724.
- Aveyard P, et al. Nicotine replacement therapy in smoking cessation. BMJ. 2016;352:i571.
