Real-world pharmacological treatment patterns of patients with young-onset Parkinson's disease in Japan: a medical claims database analysis.

Introduction: Young-onset Parkinson's disease is reported to comprise 5-10% of all Parkinson's disease cases; however, as physicians encounter a limited number of these patients, their treatment patterns are still unclear.

Methods: We performed a descriptive study using the large Japanese medical claims database to describe the epidemiology and real-world pharmacological treatment patterns of newly diagnosed patients with young-onset Parkinson's disease. Patients aged 21-50 years in whom Parkinson's disease was newly diagnosed between January 1, 2005 and March 31, 2016 were included. We excluded individuals with Parkinson's-related diseases and those using antipsychotics to eliminate the possibility of drug-induced parkinsonism. The patients' demographics, comorbidities, prescribing patterns, and changes in levodopa equivalent daily dose were analyzed.

Results: We identified 131 newly diagnosed young-onset Parkinson's disease patients (median age, 44.2 years). The most common comorbidities were depression (23.7%), hypertension (23.7%), and insomnia (22.9%). Of these patients, 122 were prescribed antiparkinson drugs. During the study period, the proportion of patients who were prescribed dopamine agonists, levodopa, and anticholinergics were 77.1%, 44.3%, and 27.5%, respectively. Dopamine agonists (49.2%) were most commonly prescribed initially, followed by anticholinergics (23.8%), levodopa (19.7%), and others (4.1%). The levodopa equivalent daily dose increased steadily with longer disease duration.

Conclusions: Dopamine agonists were most frequently prescribed during the study period and were the initial treatment of choice. We also observed a change in levodopa equivalent daily dose over the disease course. This study provides a descriptive overview of real-world prescribing patterns in young-onset Parkinson's disease patients.