Adherence to treatment guideline recommendations for Parkinson's disease in Japan: A longitudinal analysis of a nationwide medical claims database between 2008 and 2016.

Background: Adherence to the 2011 Japanese guidelines for treatment of Parkinson's disease (PD) in real-life practice is unknown.

Methods: In this retrospective longitudinal observational study, we examined patterns and trends in anti-PD drug prescriptions in 20,936 patients (≥30 years of age with newly diagnosed PD [International Classification of Diseases-Tenth code G20 or PD Hoehn and Yahr scale 1-5] and one or more prescriptions) using nationwide registry data between 2008 and 2016. Data are presented as descriptive statistics.

Results: Half (49.6%) of the patients received levodopa (L-dopa) monotherapy, followed by non-ergot dopamine agonists (DA) prescribed as monotherapy (8.3%) or with L-dopa (8.1%). Consistent with the guidelines, 75% of patients were prescribed within 13 days of initial diagnosis; L-dopa monotherapy was the most prescribed drug in patients ≥70 years of age, whereas non-ergot DA monotherapy was more likely to be prescribed than L-dopa in patients between 30 and 50 years of age. Inconsistent with the guidelines, L-dopa monotherapy was the most prescribed drug in patients between 51 and 69 years of age. Over the course of 4 years of treatment, the prescription rate of L-dopa monotherapy and non-ergot DA monotherapy decreased by 63.7% and 44.1%, respectively, whereas that of L-dopa and non-ergot DA combination therapy increased by 103.7%. Combination therapy with L-dopa, non-ergot DA, and monoamine oxidase-B inhibitors was gradually increased at a later stage.

Conclusion: These results highlight that the state of PD treatment in Japan adheres to most of the recommendations in the 2011 national guidelines, but also precedes the 2018 guidelines.