OBJECTIVES: Parkinson’s Disease (PD) is a progressive neurodegenerative disease that affects the control of movement, with a variety of symptoms such as rigidity and tremor. There is no cure for PD and the goal of treatment is to relieve symptoms. The objective of this project was to analyze drug utilization, adherence and persistence in a real-world setting, of patients with a diagnosis of PD in Quebec, Canada.

METHODS: Using data from the Régie de l’Assurance Maladie du Québec (RAMQ) database for the period from January 2010 to December 2018, a sample of PD patients was selected. Patients had to have at least one diagnosis code for PD (ICD-9 code 332.0 or ICD-10 code G20.x) and received a PD medication (levodopa, dopamine agonist, catechol-o-methyl transferase inhibitor, monoamine-oxidase-B inhibitor and/or anticholinergic drug) at least once. Treatment utilization was measured during the follow-up (the end of the RAMQ coverage). Adherence to PD treatments was estimated by calculating the medication possession ratio (MPR) that corresponds to the total number of days’ supply of medication dispensed divided by the duration of treatment. Persistence rates were measured using a Kaplan-Meier analysis.

RESULTS: A total of 1,212 patients were analyzed. The average age was 74.3 years and 56.8% were male. The drug most often used was levodopa/carbidopa (89.8%), followed by pramipexole (17.2%), and rasagiline (14.5%). A higher proportion of patients had only used 1 treatment (49.8%). Average adherences were high for all classes of treatment (MPR≥85%) and were consistent over time, i.e. from 3 months to 24 months of treatment. The discontinuation rates at 24 months for dopamine agonists, catechol-o-methyl transferase inhibitors, monoamine-oxidase-B inhibitors, and anticholinergic drugs were approximately 50% (47.6% to 49.5%), but the levodopa class discontinuation rate was lower (20.4%).

CONCLUSIONS: While on treatment, patients were adherent. However, there were high rates of discontinuation.