Management of focal epilepsy in adults treated with polytherapy in France: The direct cost of drug resistance (ESPERA study)

Purpose To estimate the direct costs associated with the current management of focal epilepsy in adults treated with a combination of antiepileptic drugs (AEDs) in France and the supplementary costs of drug resistant epilepsy as defined by the International League Against Epilepsy (ILAE) in 2009. Methods ESPERA was a multicentre, observational, cross-sectional study conducted in France in 2010. A random sample of neurologists, including specialists in epilepsy, prospectively enrolled adults with focal epilepsy treated with a combination of AEDs. Investigators classified their patients according to the 2009 ILAE criteria for drug resistance and this classification was then reviewed by two experts. All items of healthcare resource use associated with epilepsy over the previous year were documented retrospectively and valued from a societal perspective. Results Seventy-one neurologists enrolled 405 patients. After experts’ review, 70.6% of patients were classified with drug-resistant epilepsy, 22.4% with drug-responsive epilepsy and 7% with undefined epilepsy. The mean annual epilepsy-related direct costs per patient were €4485±€4313 in patients with drug-resistant epilepsy compared to €1926±€1795 in patients with drug-responsive epilepsy. In these two groups, costs of AEDs were estimated at €2603 and €1544, respectively. Patients with drug-resistant epilepsy were more often hospitalised (mean annual cost: €1270 vs. €97) and underwent more additional tests (mean annual cost: €194 vs. €53). Conclusion The direct cost of focal epilepsy in adults on AED combinations was estimated at €3850/patient/year. Drug resistance, as defined by the 2009 ILAE criteria, resulted in significant extra costs which varied with seizure frequency.