A mixed methods approach to developing an intervention to modify medication-related beliefs and support adherence in psoriatic arthritis
: (Alternative Format Thesis)

  • Liz Sheils

Student thesis: Doctoral ThesisPhD


Objective: Psoriatic arthritis (PsA) is a chronic inflammatory condition which causes variable symptoms including pain, swelling, and damage to the joints. Effective medications can alleviate symptoms, reduce disease progression, and improve quality of life. However, non-adherence provides a barrier to achieving these goals. Medication-related beliefs have been shown to influence adherence and are potentially modifiable. We currently do not know the most effective methods to change these beliefs. This research aimed to address the following question: what methods can be used to cultivate helpful medication-related beliefs for people with PsA?

Methods: Mixed methods, guided by the Medical Research Council (MRC) framework were used to address the research question. Study 1 was a systematic review and meta-analysis of randomized controlled trials that measured medication-related beliefs in people prescribed medication for long-term condition(s). The Behaviour Change Technique Taxonomy v1 (BCTTv1) was used to code intervention components. The study aimed to establish which BCTs were present in interventions that effectively changed medication-related beliefs. These BCTs were the basis of the next study. Study 2 comprised of semi-structured interviews with people living with PsA to understand their lived experience of PsA, medication, and the effective BCTs established in Study 1. Inductive reflexive thematic analysis (TA) was used to explore subjective experience of medication-related beliefs. The second analysis of the interview data used deductive template analysis and reflexive thematic analysis (TA) to investigate BCTs discussed by PsA patients, to determine patient preferences for BCTs, establish the fit of the BCTTv1 taxonomy, and discover if there were important methods to cultivate medication-related beliefs that were not captured by the BCTTv1.

Results: For Study 1, 56 trials were included randomizing 8,714 participants and 34 different BCTs were coded across the trials. In meta-analysis, interventions led to small-to-medium effects in increasing beliefs about medication need/benefit and reducing concerns about medication. Effect sizes were higher for interventions that reported a significant effect on adherence. Problem solving, Information about health consequences and Social support (unspecified), were the most prevalent BCTs. For Study 2, semi-structured interviews, four themes were reported that influenced medication- related beliefs; Theme 1) Trusting relationship with a healthcare professional; Theme 2) Understanding the potential implications of untreated PsA; Theme 3) Accessing and navigating the medication pathway; and Theme 4) Coping with the ‘cons’ of medication. Eighteen BCTs were coded in interview transcripts which were captured in three overarching themes; Foundational, Perceptual, and Practical drivers of medication-related beliefs. Seven methods were reported which influenced beliefs that were not codable using the BCTTv1 including information about medication mechanisms and peer support.

Discussion and conclusion: Overall, the themes of a trusting relationship with a HCP and access to reliable information about PsA and medication were woven throughout the studies. Simple solutions can be offered such as brief communication and BCT training for HCPs, amendments to information about medication, integration of health psychologists into psoriatic arthritis management pathways and development of PsA peer support groups. Future research could be guided by the next stages of the MRC Framework, interviewing HCPs and testing feasibility of an intervention to cultivate helpful medication-related beliefs to support adherence in PsA.
Date of Award27 Mar 2024
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorWilliam Tillett (Supervisor), Charlotte Dack (Supervisor), Sarah Chapman (Supervisor), Hannah Family (Supervisor) & Delyth James (Supervisor)

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