Cost-effectiveness of screening for HLA-B*1502 prior to initiation of carbamazepine in epilepsy patients of Asian ancestry in the United States.

OBJECTIVE: Carbamazepine, widely used in the treatment of partial and generalized tonic-clonic seizures, has been associated with life-threatening Stevens-Johnson syndrome/toxic epidermal necrolysis among some Asians. The HLA-B*1502 genotype that occurs with varying frequency among Asians is recommended for screening prior to starting carbamazepine. Our goal is to explore the cost-effectiveness of screening for the presence of this genetic allele. METHODS: We constructed a Markov model in a hypothetical cohort of adult Asian patients with epilepsy in the United States being considered for carbamazepine to investigate the cost-effectiveness of two alternative strategies: (1) no HLA-B*1502 gene allele screening and using carbamazepine and (2) HLA-B*1502 gene allele screening and starting levetiracetam in the case of a positive screen. RESULTS: For the lifetime horizon, HLA-B*1502 gene screening was the cost-effective choice compared to no gene screening, with an incremental cost-effectiveness ratio of $27 058 per quality-adjusted life-year (QALY), below the $50 000/QALY threshold in 99.69% of probabilistic sensitivity analyses. Although gene screening strategy was more expensive than a no screening strategy, it was more effective, yielding more QALYs, across all Asian ethnic groups. SIGNIFICANCE: Our analysis confirms the 2007 US Food and Drug Administration recommendation to screen for HLA-B*1502 allele before starting treatment with carbamazepine in patients of Asian ancestry in the United States.