To identify vascular risk factors (VRFs) for incident late-onset epilepsy (LOE) in older adults.

We pooled individual participant data from five US cardiovascular cohorts: ARIC, CHS, MESA, NOMAS, and WHICAP. In ARIC, CHS, MESA, and WHICAP, we used Medicare claims to ascertain new-onset epilepsy occurring after the first 2 years of continuous Medicare enrollment using an algorithm based on ICD-9 or ICD-10 codes, and anti-seizure medications. In NOMAS, which was not linked to Medicare, we identified epilepsy using self-report, medical record review, and ICD-9 or ICD-10 codes in claims of the New York Statewide Planning and Research Cooperative System. D

Demographics were assessed by self-report, and VRFs by self-report, blood measures, EKG, physical exams, and medications.

Using individual participant meta-analysis with a fixed effect for cohort, we estimated the pooled cohort hazard ratios (HR) and 95% CI from multivariable Cox models. Participants were censored at death or end of continuous Medicare enrollment.

We identified VRFs that were independently associated with incident LOE. Potential mechanisms underlying the relationships between VRFs and LOE should be examined in future studies.