Cost-effectiveness model of adjunctive lamotrigine for the treatment of epilepsy.

OBJECTIVE To predict the cost-effectiveness of lamotrigine by evaluating the costs and health outcomes in treated patients. BACKGROUND Lamotrigine adjunctive therapy has been found to be associated with decreased seizure frequency and severity in patients who are refractory to treatment with the older antiepileptic drugs (AEDs). METHODS We used a cost-effectiveness clinical decision analysis framework to assess the impact of these clinical benefits on patient health care use. The measure of effectiveness was seizure-free days gained. The measures of health care resource use included hospitalizations, outpatient and emergency department visits, surgery, and AEDs. Medical care use and cost estimates were derived from clinical trial data and published sources. Costs and effectiveness (incremental costs per seizure-free days gained) of lamotrigine adjunctive therapy versus older AEDs were compared in patients refractory to previous treatment during three time periods: the start-up year, the second year when decisions about surgery were made, and all subsequent years. RESULTS AND CONCLUSIONS The model predicts that use of lamotrigine would be associated with an overall reduction in use of other direct medical care resources (hospitalizations, outpatient visits, diagnostic and laboratory tests, and surgery). For a 10-year time horizon, the estimated cost-effectiveness ratio is $6.9 per seizure-free day gained. The model provides a flexible framework to analyze the effect of new antiepileptic drugs.