Background: Smoking rates in the UK have declined steadily over the past decades, masking considerable inequalities, as little change has been observed among people with a mental health condition. This trial sought to assess the feasibility and acceptability of supplying an electronic cigarette (e-cigarette) starter kit for smoking cessation as an adjunct to usual care for smoking cessation, to smokers with a mental health condition treated in the community, to inform a future effectiveness trial. Methods: This randomised controlled feasibility trial, conducted March-December 2022, compared the intervention (e-cigarette starter kit with a corresponding information leaflet and demonstration with Very Brief Advice) with a usual care control at 1-month follow-up. Participants were 18+ years, receiving treatment for any mental health condition in primary or secondary care in three Mental Health Trusts in Yorkshire and one in London, UK. They were also willing to address their smoking through either cessation or reduction of cigarette consumption. The agreed primary outcome measure was feasibility (consent~15% of eligible participants; attrition rate<30%). Acceptability, validated sustained abstinence and at least 50% cigarette consumption reduction at 1-month, were also evaluated and qualitative interviews conducted to further explore acceptability in this population. Results: Feasibility targets were partially met; of 201 eligible participants, 43 (mean age = 45.2, SD = 12.7; 39.5% female) were recruited (21.4%) and randomised (intervention:48.8%, n=21; control:51.2%, n=22). Attrition rate was 37.2% at 1-month follow-up and was higher (45.5%) in the control group. At follow-up (n=27), 93.3% (n=14) in the intervention group and 25.0% (n=3) in the control group reported e-cigarette use. The intervention was well received with minimal negative effects. In intention-to-treat analysis, validated sustained abstinence at 1-month was 2/21 (9.5%) and 0/22 (0%) and at least 50% reduction in cigarette consumption 13/21 (61.9%) and 3/22 (13.6%), for the intervention and control group, respectively. Qualitative analysis of participant interviews (N=5) showed the intervention was broadly acceptable, but they also highlighted areas of improvements for the intervention and trial delivery. Conclusions: Offering an e-cigarette starter kit to smokers with a mental health condition treated in the community was acceptable and largely feasible, with harm reduction outcomes (i.e. switching from cigarette smoking to e-cigarette use and substantial reduction in cigarette consumption) favouring the intervention. The findings of the study will be used to help inform the design of a main trial.

LS has received honoraria for talks, unrestricted research grants and travel expenses to attend meetings and workshops from manufactures of smoking cessation medications (Pfizer; J&J) and has acted as paid reviewer for grant awarding bodies and as a paid consultant for health care companies. All authors declare no financial links with tobacco companies, e-cigarette manufacturers, or their representatives.

ISRCTN17691451

This work was supported by Yorkshire Cancer Research (Y433). DK receives salary support from Cancer Research UK (PRCRPG-Nov21\100002). For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. Funders were not involved in the collection, management, analysis, and interpretation of data; writing of the report; or in the decision to submit the report for publication.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

Ethical approval for the study was granted by National Health System UK (NHS) Health Research Authority (REC ref:21/NE/0202). Informed consent was obtained from all participants.

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The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.