Treatment Patterns in Patients with Incident Parkinson's Disease in the United States

Background: Treatment patterns in Parkinson's disease (PD) have not been extensively studied for nearly two decades. Insurance claims are appropriate for such analysis. Objective: To understand the standard of care use of symptomatic treatments in new cases of PD and factors associated with treatment choice. Methods: Retrospective cohort study using claims data from the United States between 2008 and 2016. We used Kaplan-Meier methodology to estimate time to treatment start and switch or add-on therapy and Cox proportional hazards models to identify predictors. Results: We identified 68,532 patients eligible for treatment pattern analyses. Median time from diagnosis until first treatment was 37 days (95% confidence interval: 36-38). Two distinct patterns of treatment initiation were identified: fast initiators and patients with delayed treatment start (or no recorded treatment). Levodopa therapies were the most commonly prescribed treatment class (52.6%). Increased age was associated with shorter time to start of treatment with levodopa. Younger age was associated with shorter time to initiation of dopamine agonists and other symptomatic treatments. Patients that initiated treatment with levodopa/combinations had the fewest switches/add-ons [30.4%; median time 7.29 (6.71, 8.13) years]. Older patients had fewer switch/add-on therapies, but only in the group that started with levodopa/combination therapy. Conclusions: Time from diagnosis to treatment start was relatively short, suggesting that PD diagnosis, as reflected in the database, is closely linked to start of symptomatic treatment. Levodopa treatment remains the most common treatment, especially for older patients. Delayed treatment start was associated with increased age and comorbidity.