Incident Epilepsy Among US Medicare Beneficiaries, 2019

Background and ObjectivesEpilepsy is common among older adults, but previous incident studies have had limited ability to make comparisons across key subgroups. We aimed to provide updated epilepsy incidence estimates among older adults, comparing across age, sex, and race/ethnicity.MethodsUsing a random sample of 4,999,999 US Medicare beneficiaries older than 65 years, we conducted a retrospective cohort study of epilepsy incidence using administrative claims for 2016-2019. Sampled beneficiaries were enrolled in the Fee-for-Service (FFS) program in each of 2016-2018 and had no epilepsy claims in those years. Non-Hispanic Black and Hispanic beneficiaries were oversampled to ensure adequate cases for detailed comparisons. Incidence in 2019 was identified in the Master Beneficiary Summary File as >= 1 inpatient claim or >= 2 outpatient nondrug claims occurring at least 1 day apart (ICD-10 G40.x). Incidence models were estimated by age, sex, race/ethnicity, and combinations thereof, with adjustment for the racial/ethnic oversampling.ResultsWe identified 20,545 incident epilepsy cases. The overall epilepsy incidence rate (IR) was 393 per 100,000 (99% CI 385-400). Incidence peaked at ages 85-89 (504 [481-529]) and was higher for men (396 [385-407]) than women (376 [366-385]). The sex difference in IRs was constant with age. Incidence was higher for non-Hispanic Black (678 [653-702]) and Hispanic (405 [384-426]), and lower for non-Hispanic Asian/Pacific Islander (272 [239-305]) beneficiaries, compared with non-Hispanic White beneficiaries (354 [299-408]). The age-specific IRs significantly differed by race/ethnicity and sex, but only among non-Hispanic Black beneficiaries-where men had higher rates at younger ages and women at older ages.DiscussionWe found higher epilepsy IRs among those enrolled in the Medicare FFS system 2016-2019 than previous studies using Medicare claims data from at least a decade ago. The risk of epilepsy onset is higher for those in their late 80s, men, and non-Hispanic Black and Hispanic older adults. There is also evidence that these age-graded risks operate differently for Black men and Black women. Efforts to provide care and services that improve quality of life for older adults living with epilepsy should consider differences by multiple social characteristics simultaneously: age, sex, and race/ethnicity.