2025 American Academy of Neurology Abstract Website

Objective:

To compare demographic and geographic characteristics of U.S. Medicare beneficiaries newly diagnosed with Parkinson disease (PD) who did or did not fill a prescription for an anti-parkinsonian medication within 12 months of diagnosis.

Background:

Anti-parkinsonian medications, especially levodopa, are critical for managing motor symptoms in PD. Understanding demographic and geographic differences in medication initiation is essential to ensure equitable care.

Design/Methods:

We used comprehensive 2014-2018 Medicare data to identify incident PD cases aged 67-105 with Part D (prescription medication) coverage at diagnosis in 2017 and the following 12 months (N=54,755). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for age, sex, and race/ethnicity in relation to use of anti-parkinsonian medications within 12 months of diagnosis. We included levodopa, COMT inhibitors, MAO-B inhibitors, dopamine agonists, and anticholinergics. We also mapped medication use nationwide.

Results:

Among incident PD patients followed for 12 months, 62.2% filled a prescription for levodopa or other anti-parkinsonian medication. Older patients were less likely than younger patients to receive anti-parkinsonian medications (OR=0.966, 95% CI: 0.963-0.968 per additional year). Women had lower odds of receiving anti-parkinsonian medications than men (OR=0.92, 95% CI: 0.89-0.96). Black patients were less likely to receive anti-parkinsonian medications compared to non-Hispanic White patients (OR=0.66, 95% CI: 0.61-0.71), while Hispanic beneficiaries demonstrated intermediate levels of anti-parkinsonian medication use (OR=0.77, 95% CI: 0.72-0.83). Even when accounting for demographics, we observed the greatest use of anti-parkinsonian medications in the Central U.S., while the lowest use was seen in the Northeast and Southwest. All results remained similar with further adjustment for urban-rural status and Area Deprivation Index.

Conclusions:

Demographic and geographic differences in the use of anti-parkinsonian medications among newly diagnosed PD patients in the Medicare population suggest potential gaps in the treatment of older and minoritized beneficiaries.