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 i nterferon alfa-2b and ribavirin results in sustained loss of detectable hep atitis 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 M arkov model to estimate the cost-effectiveness of initial combination thera py with interferon and ribavirin versus interferon alone for previously unt reated patients with chronic HCV infection in Sweden. Clinical praxis and q uality adjustments were based on expert estimates and costs were gathered f rom different health care providers in Sweden. Results: Combination therapy for 24 or 48 weeks, compared to interferon alone, prolonged quality adjust ed life expectancy by 0.5 to 1.1 years at marginal cost-effectiveness ratio s of US$ 1,400 to US$ 6,000 per DQALY (discounted quality-adjusted life-yea r) for patients with genotype 1. In genotype 1.48 weeks compared to 24 week s 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 pa tients with genotype non-1, combination therapy for 24 or 48 weeks, compare d to interferon alone, prolonged quality adjusted lift: expectancy by 2.3 y ears, with combination therapy for 25 weeks bring 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 fur patients with chronic hepatitis C.