Yazidjoglou, Amelia2025-08-222025-08-22https://hdl.handle.net/1885/733767654Adolescent electronic cigarette (e-cigarette) use is increasing and recognised as a global public health priority. E-cigarette use is associated with several health risks including addiction, poisonings, burns and injuries, and smoking initiation. While adolescents are particularly vulnerable to the known negative impacts of nicotine, important long-term health effects of e-cigarettes are unknown. Preventing adolescent e-cigarette exposure underpins most e-cigarette control polices and regulation, however there is a paucity of evidence investigating the factors underlying adolescent use. To address this evidence gap, my thesis uses mixed methods to explore drivers of e-cigarette use among Australian adolescents aged 14-17 years using data from the Generation Vape Project, along with relevant contextual factors. I consider and assess the efficacy of e-cigarettes for smoking and nicotine cessation, e-cigarette social norms, how health perceptions relate to non-use, and the relationship between sports and e-cigarette behaviour. My thesis finds limited and low certainty evidence that e-cigarettes are more efficacious than nicotine replacement therapy for smoking cessation, demonstrating that widespread and easy availability of e-cigarettes is unlikely to be an appropriate population tobacco control measure. Many adolescents hold positive e-cigarette social norms including misconceptions that e-cigarettes are normal, acceptable and used by most adolescents - likely influenced by social exposure, including observing use in public spaces, media and marketing. Perceiving e-cigarette harms is associated with never-use and is protective. However, among both users and non-users, most adolescents are aware of e-cigarette health risks, suggesting use may be driven by factors more compelling than knowledge. Sport performance and physical activity is greatly valued such that it can guide e-cigarette abstinence and cessation, highlighting a novel opportunity for intervention. Overall, my thesis finds that adolescents' e-cigarette use may not be informed by accurate health evidence but by an alternate, more persuasive narrative promoted by the e-cigarette industry. Claimed e-cigarette benefits have been distorted, including by industry, such that potential cessation benefits for smokers may have been misconstrued as positive health effects applicable to all users, including young people who have never smoked, and that e-cigarettes are also a smoking prevention tool. The e-cigarette industry has marketed e-cigarettes as essential to adolescent social capital and identity, been dismissive of harms, and implied an absence of evidence equates to an absence of risk. Furthermore, by actively shaping and highlighting the smoking cessation debate, the industry has distracted and diverted resources from other priority e-cigarette research and policy areas. Sustained and comprehensive e-cigarette control is necessary to curb drivers of e-cigarette use, promote non-use and protect health. This includes reducing industry influence by restricting exposure to pro-e-cigarette marketing and promotion, limiting access, reducing product appeal, enforcing policies and implementing quality health education. There is also a need for e-cigarette research and policy agendas to be determined by public health stakeholders, and not the e-cigarette industry and its allies, to ensure all priority areas are being addressed. Adolescents offer an invaluable and unique perspective on drivers impacting their e-cigarette use and it is crucial to include their voices to ensure health messages are believable and resonant.en-AU202510.25911/T4JN-5D46