title: Development and Validation of the Parkinson's Disease Medication Beliefs Scale (PD-Rx).
abstract: 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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: 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.
authors.forename: Jori E
authors.initials: JE
authors.lastname: Fleisher
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Department of Neurology, Philadelphia, PA, USA.
authors.forename: Nabila A
authors.initials: NA
authors.lastname: Dahodwala
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Department of Biostatistics and Epidemiology., Philadelphia, PA, USA.
authors.forename: Sharon X
authors.initials: SX
authors.lastname: Xie
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Department of Neurology, Philadelphia, PA, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Mayo
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Department of Neurology, Philadelphia, PA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weintraub
authors.affiliation: New York University School of Medicine, Division of Geriatric Medicine and Palliative Care, Department of Medicine, New York, NY, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Chodosh
authors.affiliation: University of Pennsylvania Perelman School of Medicine, Department of Medicine, Philadelphia, PA, USA.
authors.forename: Judy A
authors.initials: JA
authors.lastname: Shea
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D055118:Medication Adherence / Q000523:psychology*; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000523:psychology; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
chemical_list: D000978:Antiparkinson Agents
keywords: Parkinson’s disease; Patient beliefs; adherence; health belief model; psychometric