Abstract Body:

Introduction: Epilepsy is the third most common neurological disorder in older adults after dementia and stroke. Previous research suggests that vascular risk factors (VRFs) and cardiovascular disease (CVD) are more common in people with epilepsy. Pooling multiple cohorts with detailed characterization of vascular risk factors, CVD, and harmonized epilepsy case ascertainment increases diversity of the sample to be more representative of the US population and increases the numbers of epilepsy cases for greater statistical power.
Methods: We pooled individual participant data from five cohorts, including ARIC, CHS, MESA, NOMAS, and WHICAP. For this analysis, we included participants who were 65 years of age or above. In ARIC, CHS, MESA, and WHICAP, which were linked to Medicare Claims, we included participants who had a minimum 2-year continuous Medicare enrollment and ascertained prevalent epilepsy using an algorithm based on ICD codes and antiepileptic medication. In NOMAS, which was not Medicare-linked, prevalent epilepsy cases were ascertained by telephone interview, medical record review, and ICD codes in New York Statewide Planning and Research Cooperative System (SPARCS) data. Risk factors were assessed by self report, blood measures, ECG, physical exams, and medications at cohort baseline. We calculated unadjusted prevalence of epilepsy in each risk factor category and prevalence differences and prevalence ratios adjusted for age, sex, race/ethnicity, and cohort.
Results: Among 26,476 participants, 264 had prevalent epilepsy (9.9 cases per 1,000). Unadjusted prevalence of epilepsy was higher in older age groups, women, non-Hispanic Black and Hispanic groups, those with less education, never or current smokers, heavier alcohol drinkers, those with hypertension, diabetes, high cholesterol, underweight, obesity, history of stroke or heart disease, or 2 APOE e4 alleles (Table). Adjusted prevalence of epilepsy was higher among participants in the non-Hispanic Black group (5.3 additional cases per 1,000 [95% CI: 2.1, 8.5]) and among participants who had a history of stroke (12.9 additional cases per 1,000 [95% CI: 3.5, 22.3]).
Conclusions: In this pooled cohort analysis, adjusted for age, sex, race/ethnicity, and cohort, prevalence of epilepsy in those over the age of 65 was higher among non-Hispanic Black individuals and among those with a history of stroke.