To examine migraine diagnostic and treatment disparities among Asian ethnic subgroups across U.S. counties using national electronic health record (EHR) and census data.

Asian Americans are underrepresented and aggregated into a single racial category in research, obscuring subgroup-specific disparities. Cultural, socioeconomic, and access factors may impact migraine care in Asian groups, but granular data are lacking. 

We conducted a retrospective, county-level analysis using de-identified data from Epic Cosmos and 2020 U.S. Census data, including patients with ICD-10 codes for migraine (G43), chronic migraine (G43.7), or headache (R51.9) from 2020–2024. Counties were analyzed if at least 100 patients had a migraine diagnosis and at least one resident identified with a specific Asian subgroup. We focused on the 18 most populous subgroups, representing 99% of Asian-identifying individuals. Linear regressions were adjusted for age, sex, insurance, and Social Vulnerability Index (SVI), with state-level clustering.

We identified 17,357,084 patients with headache, 3,348,223 with migraine, and 1,234,133 with chronic migraine across 1,481 counties. Among 18,502,687 individuals within an Asian subgroup, the largest were Asian Indian (23.7%), Chinese (22.2%), and Filipino (16.5%). Counties with higher proportions of Asian residents had lower rates of migraine and chronic migraine diagnoses (0.16 and 0.10 percentage point decreases for every 1% increase in Asian population, both p<0.05). Counties with more White residents showed the opposite trend, with migraine diagnoses increasing by 0.06 percentage points for every 1% increase in White residents (p<0.01). Lower diagnostic specificity rates were observed for Asian Indian, Korean, Pakistani, and Vietnamese subgroups, with ten of eighteen (56%) subgroups demonstrating significantly lower diagnostic specificity rates. CGRP targeted prescriptions were lower in several Asian subgroups, particularly Chinese (−0.33; p<0.05) and Filipino (−0.45; p<0.05).