Table 1.
Selected Model Input Values
| Variable | Base Case Value | Range in Sensitivity Analysis | Reference |
|---|---|---|---|
| Baseline cohort characteristic | |||
| Age, y, mean ± SD | 18 ± 2 | … | Assumption |
| Female sex, % | 100 | … | Assumption |
| Annual HIV infection incidence, by age, % | |||
| ≤25 y | 5.0 | 2.5–9.0 | [2, 9, 11] |
| 26–44 y | 2.1 | 1.0–4.0 | [2, 31] |
| ≥45 y | 0.85 | … | [2, 31] |
| PrEP characteristic | |||
| Long-acting PrEP effectiveness, % | 75 | 0–100 | [14, 18, 24] |
| Standard PrEP effectiveness, % | 62 | 39–62 | [8, 10] |
| HIV test characteristic | |||
| Testing frequency during PrEP receipt | Every 3 mo | 1, 6, and 12 mo | [27] |
| Background testing frequency without PrEP receipt | Every 3 y | 1, 5, 7, and 10 y | Assumption |
| Clinical characteristic after HIV infection | |||
| Initial CD4+ T-cell count, cells/µL, mean ± SD | 559 ± 236 | … | [36–38] |
| ART efficacy of first- and second-line therapies | |||
| Patients with viral suppression at 48 wk, % | 92 | 50–100 | [29] |
| Rate of failure after 48 wk, per 100 person-years | 1.4 | … | [29] |
| Increase in CD4+ T-cell count at 48 wk, cells/µL, mean | 206 | … | [29] |
| Cost, 2014 $ | |||
| Discount rate, % | 3 | 0–5 | Assumption |
| PrEP program cost | |||
| Std-PrEP drug (TDF/FTC), monthly (annually) | 6.25 (75) | … | [33] |
| LA-PrEP drug, monthly (annually) | 12.50 (150) | … | Assumption |
| Chemistry panel, per test (annually) | 15.50 (31) | … | [35] |
| HIV test, per test (annually) | 1.20 (5) | 0.50–3.00 | [35] |
| Clinic visit, per visit (annually) | 10.40 (42) | … | [40] |
| Total Std-PrEP program cost, monthly | 12.30 | … | |
| Total LA-PrEP program cost, monthly | 18.60 | 1.90–37.10 | |
| Antiretroviral therapy (annually) | |||
| First line: TDF/FTC/EFV or TDF/3TC/EFV | 192 | 100–300 | [39] |
| Second line: AZT/3TC+LPV/r | 412 | 200–600 | [39] |
| HIV load testing, cost per test | 36 | 15–55 | [35] |
| CD4+ T-cell count testing, cost per test | 7 | 3–11 | [35] |
| Routine care cost, monthly (ranges by CD4+ T-cell count) | 20–157 | … | [35, 41] |
Abbreviations: 3TC, lamivudine; ART, antiretroviral therapy; AZT, zidovudine; EFV, efavirenz; FTC, emtricitabine; HIV, human immunodeficiency virus; LA-PrEP, long-acting preexposure prophylaxis; LPV/r, lopinavir/ritonavir; PrEP, preexposure prophylaxis; SD, standard deviation; Std-PrEP, standard preexposure prophylaxis; TDF, tenofovir.