OBJECTIVES: Parkinson’s disease (PD) is a chronic neurodegenerative disorder that affects 150,000 people in Japan. The objective of this study was to evaluate the direct medical costs of PD in Japan based on real-world data.

METHODS: We performed a retrospective descriptive study using the administrative claims data from more than 400 hospitals provided by Medical Data Vision Co., Ltd. Patients who had at least one diagnosis of PD (ICD10 G20) were identified and PD-related outpatient and inpatient cost were summarized in relation to the Hoehn and Yahr (HY) severity scale. PD-related direct cost was defined as neurology outpatient visits and hospitalizations to manage PD, pneumonitis due to inhalation of food and vomit (J69.0), and fracture of femur (S72.0, S72.1).

RESULTS: Between April 2008 and December 2018, 120,353 PD patients were identified, and 16% were diagnosed with the HY scale (1,405; 3,377; 8,107; 3,887; 2,590 for HY1 to HY5). Mean age was 74.6 ± 10.9, 46.5% were male, and the mean observation duration was 443 days. Mean monthly outpatient cost was increased by HY scale (JPY 22,762; 29,322; 45,804; 56,500; 57,164; 32,937 for HY1 to HY5 and overall, respectively). Anti-Parkinson drugs cost was 50% and 70% for HY1-2 and HY3-5, respectively. A total of 17,428 PD-related hospitalization events were identified, and incidence (0.20; 0.22; 0.57; 1.63; 2.57; 0.53 times per year) and duration (24.3; 22.9; 30.4; 36.4; 51.1; 36.3 days) were also increased by HY scale. The total cost of hospitalization related to PD by HY scale were JPY 985K; 940K; 1,176K; 1,398K; 1,727K; and for all PD patients was 1,379K, where two-thirds of costs were admission charges.

CONCLUSIONS: Direct medical costs of PD in Japan were increased by the severity of disease.