Improving medication adherence in older adults prescribed polypharmacy

  • Deborah Patton

Student thesis: Doctoral ThesisDoctor of Philosophy


Medication adherence is vital to ensuring optimal patient outcomes, particularly amongst older adults prescribed polypharmacy. However, complex interventions aimed at improving adherence have shown only limited effectiveness. To maximise effectiveness, the Medical Research Council (MRC) supports the use of both evidence and theory in developing interventions. Feasibility and pilot testing is then recommended to optimise interventions in advance of definitive trials. The aim of this research was to develop a novel complex intervention (using evidence and theory) to improve adherence in older adults (prescribed polypharmacy) and to test the feasibility of delivering this in community pharmacies.
The presented research models the MRC complex intervention framework and focuses on development and feasibility testing phases. Firstly, a systematic review was conducted to address an identified evidence gap in relation to theory-based adherence interventions previously delivered to older adults prescribed polypharmacy. Qualitative research was then conducted to explore older patients’ adherence behaviour and identify determinants (barriers, facilitators) to target for change. Using the Theoretical Domains Framework (TDF) as a lens, key domains were selected for targeting and mapped to behaviour change techniques (BCTs) using established methods. These BCTs formed the basis of a complex intervention that was delivered to older patients by community pharmacists (CPs) as part of a small-scale feasibility study. In addition to exploring older patients’ adherence behaviours, further research focused on CPs’ clinical behaviour in relation to providing medication adherence support (MAS). The qualitative TDF-based methods used in the patient study were extended and a mixed methods (qualitative, quantitative) approach was used to identify determinants influencing CPs’ behaviour. Key target domains were identified and mapped to BCTs that could be directed at CPs (e.g. in a training package) to improve future implementation of the patient intervention.
The systematic review found that adherence interventions delivered to older patients prescribed polypharmacy were rarely based on theory, supporting the need for further research. The qualitative research conducted with older patients identified eight key domains (e.g. ‘Beliefs about consequences’, Memory, attention and decision process’) that could be targeted and these domains were mapped to 11 BCTs (e.g. ‘Prompts/cues’, ‘Self-monitoring’) which formed the basis of a complex intervention. The feasibility study demonstrated that the intervention was highly acceptable to both patients and CPs but some modifications were suggested. It also highlighted the need for additional research that focuses on CPs’ behaviour (i.e. MAS provision). Findings from the mixed methods study on CPs’ behaviour led to the identification of seven key domains that could be targeted for change (e.g. ‘Skills’, ‘Motivation and goals’). Eighteen BCTs were then selected for inclusion in a training package (e.g. ‘Demonstration of the behaviour’) or for delivery alongside the patient intervention in future research (e.g. ‘Rewards/incentives’) to improve implementation.
The MRC framework served as a useful guide for developing a complex intervention to improve adherence in older patients prescribed polypharmacy. This systematic theory-based approach that involved explicitly linking theoretical domains to intervention components (BCTs) will aid future replication and understanding of how the intervention aims to bring about behaviour change. Aside from targeting patients’ adherence behaviours, this research emphasised the importance of exploring the behaviours of intervention providers (i.e. CPs) to enhance implementation. Future research will involve pilot testing a refined version of the patient intervention and CP training package to establish if a definitive trial of effectiveness (e.g. randomised controlled trial) is warranted.
Date of Award17 Oct 2017
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorCarmel Hughes (Supervisor) & Cristin Ryan (Supervisor)


  • medication adherence
  • polypharmacy
  • theory
  • community pharmacy
  • older adults
  • Theoretical Domains Framework
  • pharmacists
  • Complex interventions
  • Behaviour change

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