Exploring the uptake and use of electronic cigarettes provided to smokers accessing homeless centres: a four-centre cluster feasibility study

Background Smoking prevalence is extremely high in adults experiencing homelessness and there is little evidence regarding which cessation interventions work best. This study explored the feasibility of providing free e-cigarette (EC) starter kits to smokers accessing homeless centres in the UK Objectives Seven key objectives were examined to inform a future trial. 1: Assess willingness of smokers to participate in the study to estimate recruitment rates. 2: Assess participant retention in the intervention and control groups. 3: Examine the perceived value of the intervention, facilitators and barriers to engagement and influence of local context. 4: Assess service providers’ capacity to support the study and the type of information and training required. 5: Assess the potential efficacy of supplying free EC starter kits. 6: Explore the feasibility of collecting data on contact with health care services as an input to a main economic evaluation. 7: Estimate the cost of providing the intervention and usual care. Design A prospective cohort four-centre pragmatic cluster feasibility study with embedded qualitative process evaluation. Setting Four homeless centres. Two residential units in London, England. One day centre in Northampton, England. One day centre in Edinburgh, Scotland. Intervention Intervention arm: A single refillable EC was provided with e-liquid provided once a week for four weeks (choice of three flavours: fruit, menthol, tobacco and two nicotine strengths: 12mg/mL or 18mg/mL). Written information for EC use and support. Usual care arm: Written information on quitting smoking (adapted from NHS Choices) and signposting to the local stop smoking service (SSS). Results Fifty-two percent of eligible participants invited to take part in the study were successfully recruited (56% in the EC arm; 50.5% in the UC arm; total N=80). Retention rates were 75%, 63% and 59% respectively at 4, 12 and 24 weeks. The qualitative component found perceived value of the intervention was high. Barriers were participant’s personal difficulties and cannabis use. Facilitators were participants’ desire to change, free EC and social dynamics. Staff capacity to support the study was generally good. Carbon Monoxide (CO) validated sustained abstinence rates at 24 weeks were 6.25% (3/48) in the EC arm vs. 0/32 (0%) in the UC arm (intention to treat). Almost all participants present at follow-up visits completed measures needed for input into an economic evaluation although information about staff time to support UC could not be gathered. The cost of providing the EC intervention was estimated to be £114.42 per person. Estimated cost could not be completed for UC. Limitations Clusters could not be fully randomised due to lack of centre readiness. The originally specified recruitment target was not achieved and recruitment was particularly difficult in residential centres. Blinding was not possible for the measurement of outcomes. Staff time supporting UC could not be collected. Conclusions The study was associated with reasonable recruitment and retention rates and promising acceptability in the EC arm. Data required for full cost-effectiveness evaluation in the EC arm could be collected but some data was not available in the UC arm. Future work: Future research should focus on several key issues to help design optimal studies and interventions with this population, including: which types of centres the intervention works best in; how best to retain participants in the study; how to help staff to deliver the intervention and how best to record staff treatment time given the demands on their time