Qualitative evaluation of adherence therapy in Parkinson's disease: a multidirectional model

Background: Medication can control the symptoms of Parkinson's disease (PD). Despite this, non-adherence with medication is prevalent in PD. Treatments for improving adherence with medication have been investigated in many chronic conditions, including PD. However, few researchers have evaluated their interventions qualitatively. We investigated the acceptability and potential mechanism of action of adherence therapy (AT) in PD patients and their spouse/ carers who received the intervention as part of a randomized controlled trial. Methods: Sixteen participants (ten patients and six spouses/carers) who had recently completed the trial were purposely selected in order to cover a range of ages and disease severity. Semi-structured interviews were conducted in the participants' homes. Data were transcribed and analyzed using a thematic approach. A second researcher, naive to PD and AT, analyzed the data independently to limit bias. Results: The trial showed that AT significantly improved both medication adherence and quality of life in people with PD. Specifically, patients who received AT reported improvements in mobility, activities of daily living, emotional wellbeing, cognition, communication, and body discomfort. General beliefs about medication also significantly improved in those who received AT compared with controls. In the current qualitative evaluation, a total of 175 codes were generated, which formed eleven subthemes. These could be grouped under three overarching themes, ie, perceptions prior to AT, positive effects of AT, and attributes of AT. Conclusion: This randomized controlled trial is the first to investigate AT in PD. The acceptability and underlying mechanism of the intervention suggest a new multidirectional model of AT in PD which future research should seek to confirm. The findings provide a deeper understanding of AT and will allow clinicians to modify the delivery of the intervention by acknowledging various pathways to improved outcomes.