Table 1.
Summary of Key Model Parameters
| Parameter* | Value | Range | Source |
|---|---|---|---|
| Demographic Parameters | |||
| Total MSM population age 13–64 | 4,343,741 | 2.2–7.5 million | Calculated (9, 10) |
| HIV prevalence in MSM | 12.3% | 1–20% | Calculated (9–12) |
| Male mortality rate | 0.0043 | 0.003–0.005 | Calculated (13) |
| Disease Parameters | |||
| Average disease duration (years) | |||
| Acute HIV | 0.25 | 0.08–0.40 | (14–18) |
| Asymptomatic HIV | 7 | 6–10 | (19–22) |
| Symptomatic HIV | 3 | 1–4 | (19–22) |
| Symptomatic HIV – Treated with ART | 18 | 12–30 | (19, 22–24) |
| AIDS | 2 | 1–3 | (19–22) |
| AIDS – Treated with ART | 5 | 2–15 | (19, 22–24) |
| Sexual Behavior Parameters | |||
| Annual transmission probability per MSM partnership (MHIV+→MHIV−) | |||
| Acute HIV | 0.210 | 0.10–0.40 | (25–27) |
| Asymptomatic HIV | 0.039 | 0.02–0.08 | (19, 25–27) |
| Symptomatic HIV | 0.039 | 0.02–0.08 | (19, 25–27) |
| AIDS | 0.160 | 0.08–0.30 | (19,25–27) |
| Annual number of male partners | 3.0 | 2.0–5.0 | (19,28–30) |
| Condom usage with male partners | 40% | 30–60% | (19,31–34) |
| Treatment Parameters | |||
| Fraction who know HIV status starting ART at CD4=0.350 × 109 cells/L | 50% | 25–75% | Estimated (19, 22, 35, 36) |
| Rate of initiating ART at CD4<0.350 × 109 cells/L | 0.05 | 0–0.10 | Estimated (19, 22, 35) |
| Reduction in sexual infectivity due to ART | 90% | 50–99% | (19, 22, 26, 35, 37–44) |
| Screening Parameters | |||
| Fraction of population tested annually | 67% | 30–90% | (28, 45, 46) |
| Reduction in sexual behavior (number of male partners) due to testing and counseling | 20% | 0–50% | (19, 35, 47–49) |
| PrEP Parameters | |||
| Reduction in risk of infection due to PrEP | 44% | 10–92% | (3) |
| Time on PrEP (years) | 20 | 1–20 | Assumed |
| Change in number of male partners due to PrEP | 0% | −20%−20% | Assumed |
| Change in condom usage with male partners due to PrEP | 0% | −20%−20% | Assumed |
| Cost Parameters (2010 US $) | |||
| Annual HIV-related healthcare costs | |||
| Acute HIV | 30 | 10–500 | Calculated (7, 15, 50, 51) |
| Asymptomatic HIV – Untreated | 4,130 | 3,000–6,000 | (19, 52–54) |
| Symptomatic HIV – Untreated | 6,934 | 5,000–9,000 | (19, 52–54) |
| Symptomatic HIV – Treated with ART (excludes ART costs) | 6,181 | 5,000–7,000 | (19, 52–54) |
| AIDS – Untreated | 21,863 | 15,000–26,000 | (19, 52–56) |
| AIDS – Treated with ART (excludes ART costs) | 9,950 | 6,000–17,000 | (19, 35, 53, 54) |
| Annual non-HIV-related healthcare costs for uninfected and infected individuals | 4,061 | 3,000–6,000 | (57) |
| Annual cost of ART | 15,589 | 12,500–19,000 | (19, 35, 53, 56) |
| Cost of PrEP | |||
| TDF/FTC (30 day supply) | 776 | 300–1,118 | (5, 58) |
| STI testing | 54 | 25–75 | (59) |
| Blood urea nitrogen and serum creatinine testing | 23 | 10–40 | (59) |
| Physician visit | 100 | 10–200 | (59) |
| Cost of HIV testing – Antibody test | |||
| Uninfected | 13 | 5–25 | (59) |
| HIV-infected | 66 | 50–100 | (59) |
| Cost of counseling | |||
| Pre-test counseling | 13 | 0–100 | (60, 61) |
| Post-test counseling for HIV-negative persons | 7 | 0–50 | (60, 61) |
| Post-test linkage/counseling for HIV-positive persons | 14 | 0–100 | (60, 61) |
| Cost of HIV diagnosis | 491 | 125–1,200 | (59) |
| Annual Discount Rate | 3% | 0–5% | (8) |
*
All rates are annual. MSM = men who have sex with men, ART = antiretroviral treatment, MHIV+ = HIV-positive male, MHIV- = HIV-negative male, PrEP = preexposure prophylaxis, TDF/FTC = tenofovir and emtricitabine, STI = sexually transmitted infection.