How do people quit smoking using e-cigarettes? A mixed-methods exploration of participant smoking pathways following...

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

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.

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

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

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.

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

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

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.

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.