Evaluation of health-care utilization in patients with Dravet syndrome and on adjunctive treatment with stiripentol and clobazam

Abstract

Dravet syndrome (DS) is a rare, severe childhood epilepsy syndrome that imposes a substantial burden on patients and their caregivers. This study evaluated health-care utilization over a 2-year period in patients with DS at an outpatient clinic of a German epilepsy center. Data on the course of epilepsy, anticonvulsant treatment, and direct costs were recorded using the electronic seizure diary Epivista and patients' files. We enrolled 13 patients with DS (6 females, mean age: 12.3±7.5 years) between 2007 and 2010 and evaluated them during a 1-year baseline. All patients had drug-resistant epilepsy and their seizures failed to improve with a mean number of 6.7±3.4 anticonvulsants. They had an overall mean seizure frequency of 102.1 seizures per year (median: 31, range: 3-538) with 43.2 GTCSs per year (median: 14, range: 0-228). We estimated the annual total direct costs at €6506±3974 (range: €1174-11,783) per patient with hospitalization (68.9% of total direct costs) as the major cost factor ahead of costs for anticonvulsants (24.0%). For the 1-year follow-up period, less severely affected patients were continued on conventional anticonvulsants (n=4) or switched to adjunctive treatment with stiripentol and clobazam (n=9). In the latter group, six patients (67%) were long-term responders, with between 25% and 100% seizure reduction with respect to either GTCSs or the overall seizure frequency. This reduction in seizure frequency was associated with a shift in the distribution of cost components towards higher medication costs and decreased hospitalization costs. The total direct costs increased by 42.7%, mainly due to the newly introduced stiripentol, with an annual cost of €6610. This study showed that direct costs of patients with DS were above the average European costs of drug-resistant epilepsy in children. Treatment with new anticonvulsants resulted in reduction of seizures and inpatient admissions.

Keywords: Cost; Dravet syndrome; Economic burden; Epilepsy; Pharmacoeconomic study; Stiripentol.