Cost-effectiveness of topiramate in migraine prevention: results from a pharmacoeconomic model of topiramate treatment.

OBJECTIVE: Patients whose migraines are frequent, cause disruptions of daily routines, or are unresponsive to acute treatment are primary candidates for preventive migraine therapy. This cost-effectiveness model assesses the clinical and economic impact of topiramate (TPM) therapy versus no preventive treatment for migraine headache in the United States.
BACKGROUND: Despite significant progress in treatment options, the economic burden of migraine to patients, employers, health systems, and society is substantial. Treatment strategies for migraine are directed toward managing acute episodes. However, preventive therapy should be used for patients with frequent migraine attacks (>2 per month) or those experiencing attacks that disrupt daily routines.
METHODS: Data for the model were obtained from the published literature and pooled results of two randomized, double-blinded, placebo-controlled trials of TPM in migraine prevention. Model inputs included baseline migraine frequency (the base case assumed 6 per month, consistent with the average rate in the TPM trials), treatment discontinuation (including discontinuation due to adverse events), treatment response (ie, > or = 75%, 50% to 75%, and <50% reduction in migraine frequency), cost of preventive therapy (TPM plus physician visits for medication titration), cost of acute treatment per attack (including pharmacy and medical service costs), hours of disability per attack, hourly wage, and quality-of-life (utility) weights. Model outcomes included the number of migraines averted, disability hours, total cost of acute and preventive treatment, and lost wages. Results were expressed as cost per migraine averted and cost per quality-adjusted life years (QALY). All costs were stated as 2002 U.S. dollars. We also conducted sensitivity analyses to assess the robustness of model findings with respect to variation in key parameters.
RESULTS: We estimated that the use of TPM would prevent 1.85 migraines per patient and almost 5 hours of disability per month versus no preventive treatment. Resulting savings in cost of acute treatment (dollar 27) and work loss (dollar 51) offset 68% of the expected monthly cost of TPM (dollar 113). The incremental cost per migraine averted was dollar 19, while the incremental cost per QALY was estimated to be dollar 10,888 (dollar 26,191 when indirect costs were excluded from the analysis). Model results were sensitive to baseline migraine rate and gain in health utility from migraine prevention.
CONCLUSIONS: Economic savings associated with reduced migraine frequency offset approximately two thirds of the cost of preventive TPM therapy. The cost-effectiveness of TPM depends on utility gains associated with a reduced frequency of migraine headaches, which is the subject of ongoing research. However, results from our model suggest that the use of TPM in prevention of migraine may offer reasonable value for money relative to many well-accepted medical interventions.