Does age influence diagnostic outcomes in an adult cohort referred to a first-seizure clinic?

Objective: The aging Danish population is associated with increasing morbidity and healthcare utilization. This study examines age-related differences in resource utilization and diagnostic outcomes between older (65–95 years) and younger adults (18–64 years) evaluated for suspected epilepsy, including clinical management, diagnostic yield, and final diagnoses. Methods: This single-center retrospective cohort study used electronic health record registry data from adults referred for epilepsy evaluation at Aalborg University Hospital between April 1, 2022, and January 8, 2024, with 1-year follow-up. Patients were stratified into different age groups and the relative risk (RR) of receiving an epilepsy diagnosis was modeled using a modified Poisson regression method, with age as the primary predictor. The diagnostic yield of magnetic resonance/computed tomography (MR/CT) and the sensitivity and specificity of electroencephalography (EEG) were compared using the chi-square test and Fisher's exact test. Results: Of 530 patients evaluated, 30% received an epilepsy diagnosis and 17% were diagnosed with a first unprovoked seizure. International Classification of Diseases, 10th Revision (ICD-10) codes varied with age, and the RR for epilepsy was significantly higher in older adults 65–95 years of age compared with both adults 18–64 years of age and those 40–64 years of age. This association remained unchanged after adjustment for sex. Furthermore, 97.7% underwent neuroimaging, and 92.6% underwent an EEG. The diagnostic yield of EEG and neuroimaging (magnetic resonance imaging [MRI] and CT) did not differ significantly between the two age groups. Significance: Older adults referred for epilepsy evaluation were more likely to receive an epilepsy diagnosis. More than half of patients initially thought to have epilepsy, or a first unprovoked seizure, were ultimately assigned a diagnosis other than epilepsy after comprehensive clinical assessment. These findings underscore the importance of careful, age-sensitive diagnostic evaluation, and highlight the need for further research to elucidate age-related diagnostic patterns and refine inclusion criteria and workup strategies in first-seizure clinics.