| Variable | Base-Case Assumptions | Source (Reference) |
Adults with HCV Infection among 1000 Average-Risk Adults Screened | Adults with HCV Infection among 1000 Adults Screened Who Reported IV Drug Use |
|---|---|---|---|---|
| Prevalence of anti-HCV antibodies in population | 2% in general U.S. population 50 to >90% in U.S. patients with past or current IVDU | NHANES III3 (1.8% in general population, 2.3% in adults>20 years old) Numerous cross-sectional studies |
20 | 500-900 |
| Proportion of anti-HCV antibody positive patients (positive results on ELISA followed by confirmatory RIBA) with viremia | 73%-86% | NHANES III3, Dionysos study (Italy),37 French population-based study,2 Italian population-based study91 | 15-17 | 365-774 |
| Proportion of patients with viremia who will develop cirrhosis after 10-20 y | 0%-10% | Systematic review of community-based cohorts of patients with HCV infection14 | 0-1.7 | 0-77 |
| Proportion of patients with viremia who have abnormal aminotransferase levels | 54%-66% | Dionysos study (Italy),37 French population-based study,2 Italian population-based study91 | 8-11 | 197-511 |
| Proportion of patients undergoing liver biopsy who have major complications | 1%-2% for major complications (bleeding, death, perforation) <0.3% mortality | 1 large fair-quality observational study with independent ascertainment of complications in patients referred for biopsy for a variety of indications;107 numerous other poor- and fair-quality observational studies (small studies of patients with HCV infection suggest a lower rate of complications) | 0.15-0.34 major complications and <0.05 deaths if all patients with viremia undergo biopsy 0.08-0.22 major complication and <0.03 death if only patients with abnormal aminotransferase levels undergo biopsy |
4-15 major complications and 0-2 deaths 2-10 major complications and 0-1.5 deaths |
| Proportion of patients referred for evaluation of HCV infection who received therapy | 30% | 3 fair-quality observational studies of patients referred for evaluation of HCV infection100-102 | 4-5, if all patients with viremia referred 2-3, if only patients with abnormal aminotransferase levels referred |
110-232 59-153 |
| Proportion of patients who received interferon-based therapy who completed treatment course | 80%-90% | Numerous good-quality randomized trials and systematic reviews33,118-128 | 4-5, if all patients with viremia referred 2-3, if only patients with abnormal aminotransferase levels referred |
88-209 47-138 |
| Proportion of patients who received interferon-based therapy who had a serious or life-threatening adverse event | 1%-2% | Numerous good-quality randomized trials and systematic reviews33,118-128 | 0.04-0.09, in all patients with viremia referred 0.02-0.06, if only patients with abnormal aminotransferase levels referred |
1-4 0.5-2.8 |
| Proportion of patients who receive treatment that have a sustained virologic response to best available therapy (pegylated interferon and ribavirin) | 54%-60% for pegylated interferon and ribavirin combination therapy | 3 randomized clinical trials (2 good-quality, 1 fair-quality) for pegylated interferon and ribavirin122-124 | 2-3, if all patients with viremia referred 1-2, if only patients with abnormal aminotransferase levels referred |
59-139 32-92 |
* HCV = hepatitis C virus; IV = intravenous; NHANES III = National Health and Nutrition Examination Survey III. | ||||