Table 1

Parameters to populate each model compartment at inception (year 2009)

Parameter/data item			Symbol‡	Mean value	Data source	Sampling distribution	95% credible interval
Number of PWID in Scotland (in 2009)			α	15 300	24	Sampled from the posterior distribution of Prevost et al24	13 270–17 180
Number of PWID in Scotland with HCV antibodies (in 2009)			γ	7550			6620–8550
Number of ever-PWID with HCV antibodies in Scotland (in 2009)			δ	47 650			33 480–67 130
Proportion of persons with HCV antibodies in Scotland that have ever injected drugs (in 2009)			ε	85%	42	N (0.85, 0.02)	82.0–88.2
Proportion of persons with HCV antibodies that spontaneously clear infection			φ	26%	24a	N (0.26, 0.018)	22.6–29.5
Number of Scottish persons living (in 2009) with treatment-induced viral clearance			η	2000	*	†
Fibrosis distribution in overall chronically infected population (2009) {	PWID	Mild	θ₁	83.5%	32	Sampled from the Posterior distribution of Hutchinson et al32	56.2–92.0
		Moderate	ξ₁	15.4%			7.4–42.0
		Cirrhosis	Ϋ₁	1.1%			0.5–2.2
	Former/never PWID	Mild	θ₂	55.4%			42.1–66.7
		Moderate	ξ₂	37.3%			27.2–50.3
		Cirrhosis	Ϋ₂	5.8%			4.4–7.9
		Decomp cirrhosis	Ψ	1.3%			1.1–2.0
		HCC	π	0.12%			0.07–0.18
Genotype distribution (%) in overall chronically infected population (2009)	1	λ_i	λ₁	48.9%	25	Non-parametric bootstrapping (see online supplementary appendix G)	48.0–49.9
	2		λ₂	5.1%			4.7–5.5
	3		λ₃	46.0%			45.1–46.9
Fibrosis distribution in infected population receiving treatment (2009) {	PWID	Mild	θ_1RX	81.1%	See online supplementary appendix E
		Moderate	ξ_1RX	16.5%
		Cirrhosis	Ϋ_1RX	2.4%
	Former/never PWID	Mild	θ_2RX	56.0%
		Moderate	ξ_2RX	26.5%
		Cirrhosis	Ϋ_2RX	17.5%
Number of PWID treated, per annum in Scotland (2007 onwards)			τ	120	17	U (60, 180)	64–181
Total persons treated for chronic HCV in Scotland, per annum (2009–2013)			µ	1000	14	†

*Unpublished data from the Scottish Clinical database.
†Not varied. ‡Symbols relate to appendix A.
PWID, persons who inject drugs; HCC, hepatocellular carcinoma.