Economic evaluation of pegylated interferon plus ribavirin for treatment of chronic hepatitis C in Thailand: genotype 1 and 6

BACKGROUND: Pegylated interferon alpha 2a, alpha 2b and ribavirin have been included to the National List of Essential Medicines (NLEM) for treatment of only chronic hepatitis C genotypes 2 and 3 in Thailand. This reimbursement policy has not covered for other genotypes of hepatitis C virus infection (HCV) especially for genotypes 1 and 6 that account for 30-50 % of all HCV infection in Thailand. Therefore, this research determined whether pegylated interferon alpha 2a or alpha 2b plus ribavirin is more cost-effective than a palliative care for treatment of HCV genotype 1 and 6 in Thailand. METHODS: A cost-utility analysis using a model-based economic evaluation was conducted based on a societal perspective. A Markov model was developed to estimate costs and quality-adjusted life years (QALYs) comparing between the combination of pegylated interferon alpha 2a or alpha 2b and ribavirin with a usual palliative care for genotype 1 and 6 HCV patients. Health-state transition probabilities, virological responses, and utility values were obtained from published literatures. Direct medical and direct non-medical costs were included and retrieved from published articles and Thai Standard Cost List for Health Technology Assessment. The incremental cost-effectiveness ratio (ICER) was presented as costs in Thai baht per QALY gained. RESULTS: HCV treatment with pegylated interferon alpha 2a or alpha 2b plus ribavirin was dominant or cost-saving in Thailand compared to a palliative care. The ICER value was negative with lower in total costs (peg 2a- 747,718vs. peg 2b- 819,921 vs. palliative care- 1,169,121 Thai baht) and more in QALYs (peg 2a- 13.44 vs. peg 2b- 13.14 vs. palliative care- 11.63 years) both in HCV genotypes 1 and 6. CONCLUSION: As cost-saving results, the Subcommittee for Development of the NLEM decided to include both pegylated interferon alpha 2a and alpha 2b into the NLEM for treatment of HCV genotype 1 and 6 recently. Economic evaluation for these current drugs can be further applied to other novel medications for HCV treatment.