Affiliations: [a] The Marlene and Paolo Fresco Institute for Parkinson’s and Movement Disorders, New York University School of Medicine, Departments of Neurology and Population Health, New York, NY, USA
University of Pennsylvania Perelman School of Medicine, Department of Neurology, Philadelphia, PA, USA
University of Pennsylvania Perelman School of Medicine, Department of Biostatistics and Epidemiology., Philadelphia, PA, USA
New York University School of Medicine, Division of Geriatric Medicine and Palliative Care, Department of Medicine, New York, NY, USA
University of Pennsylvania Perelman School of Medicine, Department of Medicine, Philadelphia, PA, USA
Correspondence to: Jori Fleisher, MD MSCE, 240 E. 38th Street, 20th Floor, New York, NY 10016, USA. Tel.: +1 646 501 9259; Fax: +1 212 263 7721; E-mail: [email protected].
Abstract: Background: Medication non-adherence is common in Parkinson’s disease (PD) and is associated with increased disability and healthcare costs. Individuals’ beliefs regarding their medical conditions and treatments impact medication adherence. While instruments exist to measure patients’ beliefs about medications in general, no such tool exists for PD. Objectives: Create an instrument eliciting medication beliefs of persons with PD; identify demographic and clinical characteristics associated with beliefs; and examine whether beliefs are associated with dopaminergic therapy adherence. Methods: We developed the Parkinson’s Disease Medication Beliefs Scale (PD-Rx) in four phases: focus groups of patients and caregivers to generate items, scale development, expert and patient revision of items, and a cross-sectional validation sample (n = 75). Adherence was calculated using two approaches incorporating self-reported medication lists. Results: The PD-Rx consists of 11 items covering benefits and risks of PD pharmacotherapies. The scale covers motor improvement, current adverse effects, and future concerns. Higher scores indicate more positive beliefs. Internal consistency was acceptable (Cronbach’s alpha = 0.67). Test-retest reliability was 0.47. Quality of life was associated with PD-Rx scores, and lower scores were associated with non-adherence. Conclusions: Negative beliefs about PD treatments are associated with lower quality of life and may be related to medication non-adherence. Further study of any causal relationship between beliefs and medication non-adherence in PD will inform the design of future patient-centered interventions to improve adherence.
Keywords: Patient beliefs, psychometric, adherence, health belief model, Parkinson’s disease