Tobacco use remains a leading cause of preventable mortality, with individuals experiencing severe mental illness (SMI) being disproportionately affected, facing a life expectancy reduced by 13-30 years. Despite comparable motivation to quit, people with SMI are underserved by cessation services. This thesis examines best practice in smoking cessation for SMI by integrating ‘top-down’ evidence from the literature with ‘bottom-up’ insights from practice. A systematic review confirmed that people with SMI can successfully quit using interventions effective in the general population, whilst highlighting the growing use of digital tools to do so. Two empirical studies within inpatient mental health services were conducted. Study 1, conducted within the national Quality Improvement in Tobacco Treatment (QUiTT) Collaborative, found that staff alignment around cessation goals, effective use of outcome measures, and empowerment to enforce smoking cessation policies facilitated engagement, though translation into patient and service outcomes remained unclear. Study 3, using the Positive Deviance approach to investigate individual level high performance, revealed that successful practice was shaped by language framing, rapport-building in informal ‘third spaces,’ and interdisciplinary collaboration, with service users emphasising empathetic staff and timely access to nicotine replacement therapy as essential.
Synthesised through triangulation, these findings reinforced the value of motivational interviewing and relationships between ward staff and Tobacco Dependency, whilst divergences highlighted cultural barriers, alongside the absence of electronic cigarettes from the evidence base- despite their ground level acceptability. A gold standard for cessation in SMI is proposed, emphasising careful use of language, embedding motivational approaches into ward practices, prioritising staff-advisor relationships, and ensuring access to high quality e-cigarettes, supported by rigorous evaluation. This thesis contributes to reducing health inequalities by offering a holistic account of smoking cessation practice in SMI, where the rigour of research evidence meets the realities of frontline care.
