Cost-effectiveness of add-on therapy with pregabalin in patients with refractory partial epilepsy

Purpose: To estimate the cost-effectiveness of pregabalin as add-on therapy in patients with refractory partial epilepsy. Methods: We developed a model to estimate clinical and economic outcomes over 1 year in a hypothetical cohort of patients with refractory partial epilepsy assumed alternatively to receive add-on therapy with pregabalin (300 mg/day) or no add-on therapy. For each patient in the model, we estimated the occurrence of seizure and side effects, using techniques of stochastic simulation. We assigned health-state utilities to each day of follow-up based on whether or not seizure or side effects were predicted to occur. Patients could discontinue therapy due to lack of efficacy or side effects. Outcomes included expected numbers of days without seizure ("seizure-free [SF] days"), quality-adjusted life-years (QALYs), and costs of therapy. Cost-effectiveness was assessed alternatively in terms of incremental cost per SF day gained and incremental cost per QALY gained. Results: Add-on therapy with pregabalin was estimated to result in an average gain of 23.8 SF days over one year; the estimated additional cost of therapy was $678. Incremental cost (mean, 95% CI) per SF day gained was $28.45 ($27.25, $29.44); corresponding estimates of incremental cost per QALY gained were $52,893 ($49,249, $56,983). Conclusions: In patients with refractory partial epilepsy, the cost-effectiveness of pregabalin 300 mg/day compares favorably with published estimates of cost-effectiveness for other add-on antiepileptic drugs.