Chronic hepatitis B treatment: the cost-effectiveness of interferon compared to lamivudine.

OBJECTIVE To perform a cost-effectiveness evaluation from the perspective of the Brazilian National Health System of alternatives strategies (i.e., conventional interferon, pegylated interferon, and lamivudine) for the treatment of patients with chronic hepatitis B who present elevated aminotransferase levels and no evidence of cirrhosis at the beginning of treatment. METHODS A Markov model was developed for chronic hepatitis B (hepatitis B antigen e [HBeAg] positive and negative) with 40 years' time horizon. Costs and benefits were discounted at 5%. Annual rates of disease progression, costs due to complications, and the efficacy of medicines were obtained from the literature. One-way and probabilistic sensitivity analysis evaluated uncertainties. RESULTS For HBeAg positive patients, peginterferon (48 weeks) resulted in an increase of 0.21 discounted life-years gained compared to interferon (24 weeks). The incremental cost-effectiveness ratio (ICER) converted to US dollars using the 2009 purchasing power parity conversion factor was US$100,752.24 per life-year gained. For HBeAg negative patients, it was observed that interferon (48 weeks) compared with long-term lamivudine presented an increase of 0.45 discounted life-years gained and ICER of US$15,766.90 per life-year gained. In the sensitivity analysis, the ICER was more sensitive to variation in the probability of transition from chronic hepatitis B to compensated cirrhosis, discount rate, and medicine prices. Cost-effectiveness acceptability curve for HBeAg positive (pegylated interferon vs. conventional interferon) and negative (conventional interferon vs. lamivudine) showed that conventional interferon was cost-effective until three times the gross domestic product per capita. CONCLUSIONS For patients with chronic hepatitis B with elevated aminotransferase levels in the pretreatment and no cirrhosis who were HBeAg positive, pegylated interferon (48 weeks) provided more life-years gained when compared to conventional interferon (24 weeks), and the ICER surpasses the country's buying power, which makes conventional interferon the chosen alternative. For HBeAg negative patients, conventional interferon (48 weeks) compared to lamivudine provided more life-years gained at a favorable ICER.