An investigation into tobacco dependency medication adherence behaviours and their role in the treatment of tobacco addiction

Sanders, Carol Jane (2025). An investigation into tobacco dependency medication adherence behaviours and their role in the treatment of tobacco addiction. University of Birmingham. Ph.D.

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Abstract

Effective pharmacotherapy is central to tobacco dependence treatment, yet medication adherence remains a persistent challenge, undermining both clinical outcomes and the internal validity of randomised controlled trials (RCTs). This thesis adopts a mixed-methods approach to critically examine the personal, relational, and structural factors influencing adherence to tobacco dependence medications (TDMs) among individuals seeking support through NHS stop smoking services (SSS). The research integrates three interrelated components: (1) a meta-ethnography synthesising qualitative studies on TDM adherence; (2) a primary qualitative study exploring beliefs and experiences of smokers using pharmacotherapy; and (3) a retrospective critical appraisal of adherence patterns within a pragmatic RCT evaluating nortriptyline plus nicotine replacement therapy. Guided by a critical realist perspective and informed by the PRIME theory of motivation, the study embraces methodological pluralism to offer a pragmatic, theory-driven analysis of real-world adherence behaviours. Findings reveal that adherence to TDMs is shaped less by isolated individual factors and more by dynamic psychosocial processes, health service interactions, and systemic constraints. Participants’ beliefs about medication efficacy, side effects, and autonomy often conflicted with biomedical assumptions embedded in standard treatment paradigms. Communication quality, relational continuity, and practitioner empathy emerged as pivotal determinants of engagement. The RCT analysis highlighted inconsistent adherence and exposed design limitations related to participant selection, attrition, and measurement validity, underscoring the need for multilevel strategies in trial design and implementation. This thesis contributes to the field by advancing a nuanced understanding of medication adherence as a socially situated, context-sensitive phenomenon. It proposes a shift from narrow behaviourist models toward personalised, relational approaches to adherence support. Furthermore, it emphasises the importance of authentic patient and public involvement (PPI) in research co-design, particularly in shaping future TDM trials that are both scientifically rigorous and patient centred. Considering evolving post-pandemic health behaviours, widening inequalities, and an expanding digital health landscape, the findings remain timely and relevant. Recommendations include embedding co-produced adherence strategies within routine SSS delivery, integrating psychosocial screening tools, and redesigning RCTs to reflect real-world complexities. Future research should further explore critical ‘decision points’ in medication trajectories, such as initiation, discontinuation, and re-engagement, within the lived contexts of smokers navigating cessation.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):