Table 1.

Key parameters of the model

Parameter	Value	References
Population size	4,000	[2]
Average number of injecting partners during the injecting career	12	Derived from [38]
Initial distribution (HCV infection and cascade of care)
Susceptible with high risk (recent initiation of injection)	10.10%		SurvUDI, 2012–2014, unpublished data
Susceptible with low risk (experienced PWID)	36.80%
Acute hepatitis C	0%a
Non-detected chronic hepatitis C	8.40%		SurvUDI, 2012–2014, unpublished data
Detected, non-linked to care chronic hepatitis C	24.40%
Detected and linked to care chronic hepatitis C	15.30%
Under treatment	0.40%
Non-responders after treatment	4.60%
Initial distribution in the natural history model
F0/F1	61.1%		(Private communication, J. Bruneau)
F2/F3	23.3%
F4	15.6%
Decompensated cirrhosis	0%a
HCC	0%a
Infection rate by injecting partner in Susceptible (low risk)	0.025 y−1partner−1	Fitted by Approximate Bayesian Computation (ABC) to have a 22.1/100 p-y baseline incidence (SurvUDI, 2010–2013)
Mean time from the end of acute hepatitis C to detection	2.0y	Derived from SurvUDI, 2012–2014, unpublished data
Mean duration of the high-risk period, i.e. Susceptibles (high risk, recently initiated PWID)	4.0y	[39]
Mean time before linkage to care	1.7y	Derived from Notifiable Disease Reporting System of the Montréal Public Health Department
Loss to follow-up rate	10.3%/y	Derived from SurvUDI, 2012–2014, unpublished data
Treatment initiation rate when linked to care	5%/y	Approximate value derived from SurvUDI, 2012–2014, based on current number of people under treatment (0.4%)
Treatment: incoming DAAs regimens
Duration	12 weeks		[9–14]
SVR rate – treatment naive - all genotypes- clinical trials	90%
Mean duration of injecting career	9.5y		[43]

PWID people who inject drugs; SVR: sustained virological response

^aHypothesis