Table 1.

Model Parameterization and Sources

Parameter	Value (sampling range for sampled parameters)	Source
Calibration parameters (not sampled)
HCV primary incidence among HIV-diagnosed MSM (by year)	1996–1999: 0.56/100 person-years (95% CI, .08–3.96); 2000–2003: 0.48/100 person-years (.12–1.92); 2004–2007: 1.23/100 person-years (.76–1.98); 2008–2012: 2.76/100 person-years (2.12–3.61)	Berlin estimate from HIV Seroconverter cohort [6]; unpublished data
HCV prevalence (antibody or RNA positive) among HIV-diagnosed MSM in 2012	9.8% (95% CI, 8.2%–11.7%)	Berlin estimate from HIV Seroconverter Cohort [6]; unpublished data
HCV reinfection incidence after treatment or spontaneous clearance, 2002–2014	8.2/100 person-years (95% CI, 5.6–12.1)	[17]
No. of HIV-diagnosed MSM in 2014	10 500 (95% CI, 9800–11 400)	Special query from the model underlying HIV estimation for Germany (as reported in [18])
Sampled input parameters
Life expectancy from HIV diagnosis	Varies over calendar time based on increasing ART coverage and earlier diagnosis (20–40 y from assumed HIV diagnosis and ART initiation at age 35 y [19])	Based on UK data [19–21]a
Excess liver-related mortality rate due for those with chronic HCV (annual)	0.16/100 person-years (sampled uniformly from 0.05–0.27)	[22, 23]
Proportion of HIV-infected MSM with spontaneous clearance of acute HCV infection	15% (sampled uniformly from 10%–20%)	[24, 25]; Consistent with Berlin cohort [26] estimate of 13% (95% CI, 8.8%–18.6%)
Duration of acute infection until spontaneous clearance	6 mo (sampled uniformly from 3–9 mo)	[25]
HCV testing rate per year	Twice yearly from 2003	Unpublished data from Berlin cohort [26]
Duration from diagnosis to treatment (if treated)	6 mo
Proportion of those infected without spontaneous clearance who start treatment within 6 mo after diagnosis	80% from 2002 (excluding those with spontaneous clearance of virus)	In Berlin cohort, 86% of diagnosed infections were treated in 2002–2013 [26]; high treatment rates were also seen across Germany (55%–83% of acute infections treated each year during 2007–2015) (unpublished data from PROBE-C cohort [27])
SVR with interferon and ribavarin
<1 y After HCV infection	70% (sampled uniformly from 65%–75%)	[28]
>1 y After HCV infection	30% (sampled uniformly from 25%–35%)	Weighted based on genotype distribution and SVR by genotype from a recent meta-analysis [29])
SVR with direct-acting antivirals	90%	Assumed; 92% observed among HIV-infected G1 individuals across Germany [30]; 93% observed in Berlin German hepatitis C cohort (GECCO) cohort
Year of HCV epidemic seeding	1996	[31]
Proportion of HIV-infected MSM infected with HCV on HIV diagnosis	0.65% (sampled uniformly from 0.34%–1.14%)	HIV Seroconverter Cohort [6]; unpublished data
Background HCV incidence from outside HIV-diagnosed MSM population	1.5/1000 person-years (sampled uniformly from 1–2)	Assumed similar to incidence observed in HIV-uninfected MSM population [32]

Abbreviations: ART, antiretroviral therapy; HCV, hepatitis C virus, HIV, human immunodeficiency virus; MSM, men who have sex with men; SVR, sustained viral response.

^aThe proportions of HIV-diagnosed persons taking ART were similar between the United Kingdom and Germany (in 2004, 70% in both; in 2014, 90% in the United Kingdom and 80% in Germany [19]), and the median ages at HIV diagnosis were similar (34 and 33 years, respectively, in 2014). We fit a linear curve to life-expectancy data among HIV-diagnosed individuals who start ART at age 35 years from 1997 to 2008 over calendar time among a UK cohort [20]. Uncertainty was included in these fits by sampling each life-expectancy point estimate from the distribution reported in the study and refitting the linear curves. We assume a continued increase in life expectancy from 2008 until a life expectancy of 75 years is reached (consistent with model estimates of life expectancy in a high-diagnosis setting [21] and achieved in 2010 in the model).