Pharmacoeconomic analysis of the treatment of chronic hepatitis C with peginterferon alfa-2a or peginterferon alfa-2b plus ribavirin in Spain.

BACKGROUND: An independent meta-analysis of randomized comparative trials of peginterferons alfa-2a and alfa-2b, both combined with ribavirin, analyzed the probability of achieving a sustained virological response (SVR).

OBJECTIVE: To estimate the long-term cost-effectiveness of treatment of patients with chronic hepatitis C with peginterferon alfa-2a (180μg/week) plus ribavirin (800-1200mg/day) vs. alfa-2b (1.5μg/kg/week) plus ribavirin (800-1400mg/day), from the perspective of the Spanish National Health System.

METHODS: A Markov model was developed with 7 health states to simulate lifetime disease progression. SVR was calculated from the meta-analysis data. Transition probabilities and health state utilities were obtained from published literature. Direct healthcare costs were obtained from the drug catalog, while costs of disease-related complications were obtained from published studies and healthcare cost database. Costs were expressed in 2010€. The annual discount rate applied was 3.5% for both costs and benefits.

RESULTS: SVR rate for treatment with alfa-2a was higher than with alfa-2b; the differences were 6.0%, 7.6% and 8.7% for all genotypes, genotypes 1/4 and genotypes 2/3, respectively. Each patient would gain 0.469, 0.600 and 0.685 life-years and 0.155, 0.198 and 0.227 quality-adjusted life-years with alfa-2a vs. alfa-2b, for the respective genotypes. The cost saving per patient treated with alfa-2a would be €705, €672 and €1900, for all genotypes and for genotypes 1/4 and 2/3, respectively, alfa-2a being dominant.

CONCLUSIONS: According to the present model, treatment of patients with chronic hepatitis C with peginterferon alfa-2a is cost-effective compared with peginterferon alfa-2b, both combined with ribavirin.