Table 2.
Model parameters and values used during sensitivity analysis
| Parameter | Baseline value | Sensitivity | Source (where available) |
| λ0 = force of infection for new initiates | 0.1608 | 0.1314–0.1942 | [13] |
| λ1 = force of infection for experienced IDUs | 0.0526 | 0.0310–0.0863 | [13] |
| Cost of Doctor | £3.49/min (£209.40/hr) | GP:/home visit/min With Qualification costs With direct care staff costs[23] | |
| Cost of Nurse | £54/hour | District Nurse (midpoint grade G)/hr with patient + extra costs[23] | |
| Time Taken for BBV lecture/prisoner | 10 patients/hr | 1 patient/hr – 20 patients/hr | [9] |
| % Nurse time | 50% | 0–100% | |
| % Doctor time | 50% | 0–100% | |
| Time taken to verbal test on reception into prison | 5 min | 1–15 min | [24] |
| % Nurse time | 50% | 0–100% | [24] |
| % Doctor time | 50% | 0–100% | [24] |
| % Known HCV positive and say so | 55% (midpoint) | 23%–83% | 23%[10], 83%[16], |
| % never received a positive HCV test but say they are HCV positive | 1% | 0%–10% | |
| % IDUs that report IDU use (current or ever) | 75% | 30–90% | Darke[17] reports that IDUs give reasonably reliable answers to questions about drug use. |
| % non-IDUs that report IDU use (current or ever) | 0% | 0–20% | |
| Time Taken to Counsel prior to an ELISA test | 25 min | 10–60 min | 25 min[3] 10–60 min[24] |
| % Nurse time | 50% | 0–100% | [24] |
| % Doctor time | 50% | 0–100% | [24] |
| Time taken to Administer ELISA test | 5 min | 1–10 min | |
| % Nurse time | 50% | 0–100% | |
| % Doctor time | 50% | 0–100% | |
| Cost of ELISA test | £12 | £5–20 | Virus reference department, HPA, Colindale (2005) |
| % of those offered who accept ELISA testing | 85% | 10–100% | [24] |
| ELISA Sensitivity | 97% | 90–100% | [24] |
| ELISA Specificity | 99% | 90–100% | [24] |
| Time taken to administer PCR test | 5 min | 1–10 min | |
| % Nurse Time | 50% | 0–100% | |
| % Doctor Time | 50% | 0–100% | |
| % of those offered who accept PCR testing | 100% | 50% | Assuming that those that accept an ELISA test will then accept a PCR |
| PCR Sensitivity | 100% | 99%–100% | [24] |
| PCR specificity | 100% | 99–100% | [24] |
| Cost of PCR test | £57 | £50–80 | Virus reference department, HPA, Colindale (2005) |
| Time taken to counsel the result of negative ELISA or PCR test | 5 min | 5–15 min | |
| % Nurse time | 50% | 0–100% | |
| % Doctor time | 50% | 0–100% | |
| Time taken to counsel the result of a positive ELISA test | 25 min | 15–75 min | [24] 15–75 min[24] |
| % Nurse time | 50% | 0–100% | |
| % Doctor time | 50% | 0–100% | |
| Time taken to counsel the result of a positive PCR test | 25 min | 15–75 min | [24] 15–75 min[24] |
| % Nurse time | 50% | 0–100% | |
| % Doctor time | 50% | 0–100% | |
| Proportion infected with HCV that become HCV RNA positive | 80% | 54%–86% | [2,25,26] |
| Rate of HCV testing and diagnosis in the community | 0.15 | 0.1–0.3 | See text |
| Discount rate for costs | 3.5% | 0%–6% | HM Treasury[18] |
| Discount rate for benefits | 3.5% | 0%–6% | HM Treasury[18] |