Differences in patterns of outpatient epilepsy-specific medication initiation after acute ischemic stroke in the Medicare population.

Objective: Acute ischemic stroke (AIS) is a leading hospitalization cause and significantly contributes to seizures among older adults. We examined outpatient epilepsy-specific medication (ESM) initiation patterns after AIS discharge in adults 65 years and older, trends over time (by stratifying the analysis from 2013 to 2021), and racial/ethnic differences.

Methods: We analyzed nationwide administrative claims data for a 20% sample of US Medicare beneficiaries (enrolled in Traditional Medicare Parts A, B, and D for at least 12 months before admission) aged ≥65 years and hospitalized for AIS between 2013 and 2021. We estimated the cumulative incidence of ESM initiation within 90 days after AIS discharge, with mortality as a competing risk and censoring person time if individuals experienced an inpatient readmission. We described drug type and stratified our analysis by race, ethnicity, US geographic region, hospital region, and year of discharge.

Results: Of 128 174 community-dwelling beneficiaries after AIS discharge, 2435 (1.9%, 95% confidence interval [CI] = 1.8%-2.0%) initiated ESM within the 90-day follow-up period and levetiracetam was the most common medication across all years (81%). Mean age was 79 years (range = 65-110), 56% were female, 81% were non-Hispanic White, 10% were Black/African American, 5% were Hispanic, and 3% were Asian. The cumulative incidence of ESM initiation at 90 days in the overall sample was 1.4% (95% CI = 1.3%-1.4%); it was 1.8% (95% CI = 1.6%-2.1%) for Black/African American, 1.9% (95% CI = 1.6%-2.3%) for Hispanic, and 1.2% (95% CI = 1.2%-1.3%) for non-Hispanic White beneficiaries. The 90-day cumulative incidence also varied by US Census division, from 1.0% (95% CI = .8-1.3; West North Central) to 1.5% (95% CI = 1.3%-1.8%; East South Central). We observed an increase in ESM 90-day initiation over time, from 1.2% (95% CI = 1.0%-1.5%) in 2013 to 1.7% (95% CI = 1.5%-1.9%) in 2021. ESM initiation was 1.6% (95% CI = 1.4%-1.8%) in the 65-70-year age group and decreased in older age groups.

Significance: Black/African American and Hispanic beneficiaries had a higher 90-day incidence of post-AIS ESM initiation than non-Hispanic Whites. ESM initiation decreased in older age groups.