Abstracts

Rationale: Compare annual direct costs (both total and epilepsy-related) between privately insured U.S. epilepsy patients and matched controls. Methods: 4,323 patients with >1 epilepsy diagnosis (ICD-9-CM: 345.x), 1999-2004, ages 16-64 years, were selected from a privately insured claims database with 6+ million beneficiaries. Control group was an age and gender matched cohort of randomly chosen beneficiaries without epilepsy. All were required to have continuous health coverage during 2004 (baseline) and 2005 (study period). Chi-squared tests were used to compare baseline comorbidities. Wilcoxon rank-sum tests were used for univariate comparisons of annual direct (medical and pharmaceutical) costs to insurers during the study period. Results: Patients with epilepsy averaged 43 years old, and there were more females (57%). Compared with controls, epilepsy patients had significantly higher rates of mental health disorders, comorbidities included in the Charlson Comorbidity Index (e.g., cerebrovascular disease, congestive heart failure, COPD, rheumatologic disease, cancer), migraine, and other neurological disorders. On average, direct annual costs were significantly higher for epilepsy patients ($10,258) compared with controls ($3,862), difference of $6,396, P<0.0001. Outpatient services accounted for 34%, inpatient services for 28%, and drug costs for 27% of epilepsy patients’ annual direct costs. Among epilepsy patients, non-epilepsy costs accounted for $8,201 (80%) on average and epilepsy-related costs (i.e., costs for antiepileptic drugs, claims with an epilepsy or convulsions diagnosis, neurology visits, and selected diagnostic procedures) accounted for $2,057 (20%). Approximately 13% ($1,047) of non-epilepsy costs were attributable to mental health-related expenditures. Conclusions: Patients with epilepsy had significantly higher costs compared with matched controls. The excess costs of epilepsy patients are underestimated when looking only at epilepsy-related costs. Epilepsy-related costs represented 20% of the annual direct costs of epilepsy patients and almost one-third of the difference in costs between epilepsy patients and controls.