Table 1. Base case demographics, annual transition probabilities, and SVR probabilities per treatment scenario.
| Demographics | % | Source | ||
|---|---|---|---|---|
| Sex distribution | [22] | |||
| Men | 0.64 | |||
| Genotype distribution | [28] | |||
| 1–4 | 0.70 | |||
| 2–3 | 0.30 | |||
| Annual transition probabilities | ||||
| HIV-negative | HIV-positive | |||
| Acute HCV to chronic HCV | [25,29,41] | |||
| Women | 0.58 | 0.64 a | ||
| Men | 0.80 | 0.89 a | ||
| Fibrosis progression in METAVIR staging (yearly transition is a METAVIR transition) b | ||||
| Women | [30, 31] | |||
| <49 | 0.05 | 0.10 | ||
| 50 to 59 | 0.12 | 0.25 | ||
| 60 to 69 | 0.22 | 0.44 | ||
| > = 70 | 0.30 | 0.60 | ||
| Men | [30, 31] | |||
| <49 | 0.03 | 0.06 | ||
| 50 to 59 | 0.07 | 0.13 | ||
| 60 to 69 | 0.11 | 0.23 | ||
| 70–79 | 0.15 | 0.31 | ||
| > = 80 | 0.21 | 0.42 | ||
| Disease progression after cirrhosis (F4) | ||||
| To DC or HCC c | ||||
| F4 to DC | 0.039 | 0.059 | [32,42] | |
| DC to HCC | 0.068 | 0.102 | [33,42] | |
| F4 to HCC | 0.021 | 0.032 | [30,42] | |
| Death | [30] | |||
| DC to death | 0.31 | d | ||
| HCC to death | 0.43 | d | ||
| Treatment scenarios–SVR probabilities | ||||
| HIV-negative | HIV-positive | |||
| Scenario 1: PegIFN/RBV | ||||
| Genotype 1–4 (48 weeks) | [34, 35] | |||
| F0-F2 | 0.47 | 0.28 | ||
| F3-F4 | 0.33 | 0.20 | ||
| Genotype 2–3 (24 weeks) | [35, 36] | |||
| F0-F2 | 0.76 | 0.71 | ||
| F3-F4 | 0.52 | 0.47 | ||
| Scenario 2: DAA/RBV & Dual DAA | ||||
| Dual DAA therapy | [15, 37] | |||
| Genotype 1–4 (12 weeks) | ||||
| F0-F4 | 0.95 | 0.95 | ||
| DAA/RBV | [38–40] | |||
| Genotype 2–3 (22 weeks e,f) | ||||
| F0-F4 | 0.90 | 0.90 | ||
| Scenario 3&4: Dual DAA therapy | [15, 37] | |||
| All genotypes (12 weeks) | ||||
| F0-F4 | 0.95 | 0.95 | ||
Abbreviations: PegIFN: pegylated-interferon; RBV: Ribivarin; No: Number; SVR: sustained virological response; DAA: direct-acting antiviral
a Clearance rate reported to be 15 and 20% among HIV/HCV-coinfected individuals,; therefore we assumed an overall clearance rate of 17% among them. Clearance rate by sex among HIV/HCV-coinfected was proportional to that among HIV-negative individuals.
b 2 times the fibrosis progression rate of HIV-negative individuals
c 1.5 times the progression rate among HIV-negative individuals
d Not related to HIV status
e We calculated a weighted average for the number of treatment weeks for those with genotype 2–3 as those with genotype 2 should be treated for 12 weeks while those with genotype 3 should be treated for 24 weeks with SOF/RBV. We assumed that a maximum of 20% of PWID [28] in this genotype group are infected with genotype 2, therefore the weighted number of weeks of treatment is 21.6.
f At the time the model was built, data for 24 weeks treatment for genotype 3 was scarce and the Positron trial showed similar SVR among cirrhotic and non-cirrhotic patients with genotype 2. In post-hoc sensitivity analyses SVR probability for F3-F4 was set at 0.70.