Antiepileptic drug treatment patterns and economic burden of commercially-insured patients with refractory epilepsy with partial onset seizures in the United States.

OBJECTIVE: To assess the economic burden in direct healthcare utilization and costs for refractory epileptic patients with partial onset seizures (POS) and assess the antiepileptic drug (AED) treatment patterns among these patients.
METHODS: This retrospective database study analyzed administrative claims of commercially-insured patients with POS from 2004-2008. Healthcare costs and utilization were compared between refractory (defined as ≥3 AEDs) and non-refractory patients by calendar year and AED treatment patterns were described for refractory patients.
RESULTS: Of the 79,149 patients identified (mean age 33 years; 54.8% female), 8714 (11%) were classified as refractory. In 2008, average annual healthcare costs for refractory patients were significantly higher than non-refractory patients ($33,613 vs $19,085), also by settings for inpatient ($11,780 vs $6076), outpatient ($13,431 vs $8637), and pharmacy costs ($8402 vs $4372) (all p < 0.001). Among refractory patients, close to one-third of total costs were for POS-related services. Similar trends were observed when assessing POS-related utilization and costs. The differences were consistent across all calendar years examined. Among refractory patients, 80.5% were on monotherapy at the beginning of the follow-up period. Levetiracetam is the common AED in mono/combination therapy as well as add-on/switch-to. LIMITATIONS: The onset of seizure cannot be identified, and the indication of each AED could not be confirmed from the pharmacy claims. Only direct medical costs were assessed.
CONCLUSIONS: Pattern of use was very dynamic, suggesting seizures are not well-controlled. Improving seizure control and reducing economic burden of refractory epilepsy remain important unmet medical needs in this population.