How do people quit smoking using e-cigarettes? A mixed-methods exploration of participant smoking pathways following receiving an opportunistic e-cigarette-based smoking cessation intervention.

Background And Aims: Pathways of transitioning from tobacco smoking to vaping after receiving an e-cigarette-based smoking cessation intervention have been minimally explored.

Study Aims: 1) identify pathways between intervention delivery and final follow-up; 2) describe baseline and post-intervention statistical data in relation to smoking/vaping behaviour of the different pathway groups; 3) explore qualitative participant perspectives contextualising pathway groups.

Design: Embedded mixed-methods analysis of data collected for the Cessation of Smoking Trial in the Emergency Department (COSTED) randomised controlled trial.

Setting: Recruitment from 6 Emergency Departments (5 in England and 1 in Scotland) between January and August 2022.

Participants: 366 adult smokers who were randomised to receive the COSTED intervention and provided data at 6-month follow-up. Qualitative subsample of 24 participants interviewed after follow-up.

Interventions: Brief smoking cessation advice, provision of an e-cigarette starter kit and referral to the local Stop Smoking Service.

Measurements: Descriptive statistical reporting of identified pathways and smoking/vaping behaviour at baseline and 6-month follow-up. Semi-structured phone/video interviews analysed thematically.

Findings: 13.4% (n = 49) of participants quit smoking within 1 month of receiving the intervention, 19.1% (n = 70) quit between 1 and 6 months, 24.9% (n = 91) reduced cigarettes per day (CPD) by at least 50%, and 42.6% did not experience a significant smoking reduction. Approximately a third of participants who quit reported not vaping at follow-up. Reporting dual use was associated with a reduction in CPD. Appoximately a third reported experimenting with a different device to the one provided as part of the intervention. Quitters reported themes of satisfaction with vaping, changes in environment facilitating quitting and motivation to quit.

Conclusions: Dual use of cigarettes and e-cigarettes can result in a reduction of smoking and may prelude quitting smoking. Sustained e-cigarette use is not always necessary for quitting success. Success depends on personal context as well satisfaction with vaping.