Factors Associated with Medication Beliefs in Patients with Parkinson's Disease: A Cross-Sectional Study.

ABSTRACT

OBJECTIVE: Medication beliefs are a significant determinant of medication adherence in chronic illness. This study aimed to identify demographic, clinical, and medication-related factors associated with medication beliefs in patients with Parkinson's disease (PD). METHODS: We used a descriptive cross-sectional design with a convenience sample of 173 PD patients who had been taking antiparkinson drugs for more than one year. RESULTS: The subjects who believed PD medication was more necessary had more severe illness, younger age of onset, longer illness duration, and longer duration of levodopa therapy. They had higher levels of non-motor symptoms and depression, number of medication uses, number of drugs, and levodopa equivalent dose, and they reported fluctuation of motor symptoms and dyskinesia. The subjects who used catechol-O-methyltransferase (COMT) inhibitors, dopamine agonists, amantadine, and monoamine oxidase-B (MAO-B) inhibitors had significantly higher necessity scores than those who did not use them. The subjects who had higher concerns about PD medications had higher levels of non-motor symptoms and depression. The subjects using amantadine and anticholinergics had significantly higher concern scores than those who did not use them. Positive necessity-concerns differentials were associated with severe illness, the presence of motor fluctuation and dyskinesia, and the use of COMT inhibitors. Based on stepwise multiple regression, the most significant factors influencing necessity beliefs were severe illness, followed by depression and motor fluctuation. CONCLUSION: Severe illness, higher levels of depression, and motor fluctuation are independent factors influencing patients' beliefs regarding medication necessity. Therefore, these characteristics should be considered in medication belief assessment and interventions for PD patients.