Perform an updated characterization of medication utilization among PD patients prescribed levodopa or dopamine agonist (DA) treatments.

About 1% of individuals age 60+, or 1.5 million persons, are diagnosed with Parkinson’s disease (PD) in the US. Levodopa and DA are most the most common PD treatments. An updated analysis of PD medication use is needed.

Retrospective analysis using medical and pharmacy claims data from commercial and Medicare Advantage with Part D (MAPD) insurance enrollees, age 40+ with coverage between 09/01/2011-12/31/2019. Patients had ≥1 claim for levodopa or DA; first claim=index date. Patients had ≥2 PD diagnoses, continuous enrollment for 12 months pre- and post-index, and were excluded if prescribed the index treatment during the pre-index period, or both levodopa and DA on index. Kaplan-Meier analyses estimated time to index treatment discontinuation.

Patients prescribed levodopa (n=11,125) and DA (n=1,562) differed by age (mean=75 vs. 68 years, p<0.001). The levodopa cohort had higher percentages with MAPD coverage (82.4% vs. 59.8%, p<0.001) and pre-index cognitive decline (12.4% vs. 8.7%, p<0.001). The mean proportion of days covered (medication adherence measure) was higher for levodopa (0.73 vs. 0.61, p<0.001) and a higher percentage of levodopa patients continued index monotherapy throughout the post-index period (81.5% vs. 54.0%, p<0.001). The DA cohort had higher percentages with concomitant treatment (17.6% vs. 5.1%, p<0.001), switched treatment (37.2% vs. 12.9%, p<0.001) and discontinuation (50.3% vs. 35.3%, p<0.001), with shorter mean time to first treatment change (77 days vs. 100, p<0.001). Kaplan-Meier analyses predict the proportion of patients who continued index treatment after 12 months was higher for levodopa patients with commercial (64.4% vs 56.1%, p<0.001) and MAPD (64.8% vs 45.4%, p<0.001) health coverage.

Results suggest levodopa treatment occurs more consistently than DA treatment, as DA patients had relatively high treatment modification and discontinuation rates, and low medication adherence.