Table 2.
Base Case Values for Model Parameters
| Variable | Base Case |
|---|---|
| HCV natural history parameters*17,26-29,31 | |
| Fibrosis progression in men, age (years)† | |
| 0 | 0.149 |
| 50 | 0.169 |
| 60 | 0.298 |
| ≥70 | 0.406 |
| Fibrosis progression in women, age (years)† | |
| 0 | 0.108 |
| 50 | 0.135 |
| 60 | 0.208 |
| ≥70 | 0.284 |
| Cirrhosis to ascites | 0.025 |
| Cirrhosis to hepatic encephalopathy | 0.004 |
| Cirrhosis to hepatocellular carcinoma | 0.015 |
| Cirrhosis to variceal hemorrhage | 0.011 |
| Liver transplant probability | 0.031 |
| Mortality rate per person | |
| Ascites | 0.110 |
| Hepatic encephalopathy (first year) | 0.680 |
| Hepatic encephalopathy (subsequent years) | 0.400 |
| Hepatocellular carcinoma | 0.433 |
| Transplant (first year) | 0.210 |
| Transplant (subsequent years) | 0.057 |
| Variceal hemorrhage (first year) | 0.400 |
| Variceal hemorrhage (subsequent years) | 0.130 |
| Treatment parameters11 | |
| Treatment response probability | |
| Interferon-alfa + ribavirin | |
| Genotype 1 | 0.07 |
| Non-genotype 1 | 0.18 |
| Pegylated interferon-alfa | |
| Genotype 1 | 0.14 |
| Non-genotype 1 | 0.31 |
| Pegylated interferon-alfa + ribavirin | |
| Genotype 1 | 0.29 |
| Non-genotype 1 | 0.58 |
| Probability of early virologic response (EVR) | |
| Interferon-alfa + ribavirin | 0.38 |
| Pegylated interferon-alfa | 0.55 |
| Pegylated interferon-alfa + ribavirin | 0.71 |
| Treatment mortality probability | 0.002 |
| Costs (2004 US $)31,34-37 | |
| Treatment Protocol 1‡ | |
| Interferon-alfa + ribavirin | $15,568 |
| Pegylated interferon-alfa | $19,305 |
| Pegylated interferon-alfa + ribavirin | $27,880 |
| Treatment Protocol 2§ | |
| Interferon-alfa + ribavirin | $8,769 |
| Pegylated interferon-alfa | $13,109 |
| Pegylated interferon-alfa + ribavirin | $22,022 |
| Costs of annual HCV care | |
| Chronic HCV | $140 |
| Compensated cirrhosis | $1,017 |
| Ascites | $4,280 |
| Variceal hemorrhage, first year | $23,669 |
| Variceal hemorrhage, subsequent years | $4,632 |
| Hepatic encephalopathy, first year | $15,192 |
| Hepatic encephalopathy, subsequent years | $3,519 |
| Hepatocellular carcinoma | $40,828 |
| Liver transplant, first year | $134,458 |
| Liver transplant, subsequent years | $23,481 |
| Costs of annual HIV care | |
| CD4 count 200-500/mm3 | $5,096 |
| Three-drug antiretroviral therapy | $13,752 |
*
Annual rates per person are presented here except where specified, but these were converted to monthly probabilities in the model.
†
Fibrosis progression rates are assumed to be linearly interpolated in these ranges. Progression rates were the same for Metavir stages F0 to F4.
‡
All patients receive the full 48-week course of therapy.
§
Patients without an early virologic response receive only 12 weeks of therapy; protocol assumes nondrug costs by week 12 are two-thirds of nondrug costs for 48 weeks of therapy.