Economic evaluation of levetiracetam as an add-on therapy in patients with refractory epilepsy

Abstract

Objectives: This study provides the results of a cost-effectiveness analysis of levetiracetam as an adjunctive treatment for refractory epilepsy from the Canadian Ministry of Health perspective. The main objective is to estimate the expected cost-effectiveness ratio expressed as the incremental cost per seizure-free day gained when using levetiracetam. In addition, this study examines the potential savings that might result by reducing the number of surgical evaluations and surgery when using levetiracetam.

Methods: A 1-year dose escalation decision-tree model comparing levetiracetam plus standard therapy with standard therapy alone was designed in order to combine probability, resource use and unit cost data (1999 Canadian dollars [$Can]). The short-term outcomes were derived from three phase III randomised, double-blind, placebo-controlled trials performed in 904 patients, aged 16-70 years, with at least 1 year history of epilepsy, two to four partial seizures per month, and receiving a maximum of two classic antiepileptic drugs.

Results: The average gain in seizure-free days attributed to levetiracetam was 19 days per patient per year and the incremental cost-effectiveness ratio (ICER) for levetiracetam add-on in the base-case scenario was $Can80.7 per seizure-free day gained per patient per year. Moreover, when surgical investigation and surgery are considered in the model, the use of levetiracetam may be dominant, with substantial savings to the overall healthcare budget. All univariate sensitivity analyses show that the model was robust to the assumptions made.

Conclusions: The economic analysis presented in this paper suggests, given a wide range of assumptions, that the increased cost of treating patients (with refractory epilepsy) with levetiracetam may be partially offset by a reduction in other direct medical costs (from the Canadian Ministry of Health perspective), as a consequence of an increase in the number of seizure-free days. Moreover, potential cost savings may be foreseen when it is assumed that levetiracetam may reduce the number of candidates for surgical evaluation and surgery through a reduction of seizure frequency.