Cost-effectiveness of interferon alfa-2b with and without ribavirin as therapy for chronic hepatitis C in Sweden.
BACKGROUND: Recent trials have shown that treatment with a combination of interferon alfa-2b and ribavirin results in sustained loss of detectable hepatitis C-virus (HCV) RNA in a higher proportion of patients than treatment with interferon alone. Combination therapy, however, is two to three times as expensive as monotherapy. METHODS: Based on data from recent randomized clinical trials and a previously published decision model, we developed a Markov model to estimate the cost-effectiveness of initial combination therapy with interferon and ribavirin versus interferon alone for previously untreated patients with chronic HCV infection in Sweden. Clinical praxis and quality adjustments were based on expert estimates and costs were gathered from different health care providers in Sweden. RESULTS: Combination therapy for 24 or 48 weeks, compared to interferon alone, prolonged quality adjusted life expectancy by 0.5 to 1.1 years at marginal cost-effectiveness ratios of US$ 1,400 to US$ 6,000 per DQALY (discounted quality-adjusted life-year) for patients with genotype 1. In genotype 1, 48 weeks compared to 24 weeks of combination therapy prolonged quality adjusted life expectancy by 0.6 years at a marginal cost-effectiveness ratio of $US 9,800 per DQALY. For patients with genotype non-1, combination therapy for 24 or 48 weeks, compared to interferon alone, prolonged quality adjusted life expectancy by 2.3 years, with combination therapy for 24 weeks being money-saving. The results were robust in sensitivity analyses. CONCLUSION: Combination therapy with interferon and ribavirin increased quality-adjusted life expectancy and was cost-effective for patients with chronic hepatitis C.