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.

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.

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.

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.