Table I.
Input parameters for a model of a 12-month adherence intervention in youth with HIV in the United States
| Parameter | Base case value | Source |
|---|---|---|
| Cohort characteristics | ||
| Age, mean (SD) | 19.5 (3.6) | [21] |
| Male/Female sex, % | 79/21 | [69] |
| CD4 at model start, cells/µL, mean (SD) | 545 (228) | [21] |
| HIV RNA setpoint off ART | [22] | |
| Mean log10 copies/mL (copies/mL) | 5.22 (165,800) | |
| Distribution, % of cohort | ||
| >100,000 copies/mL | 25.1 | |
| 30,001–100,000 | 42.0 | |
| 10,001–30,000 | 20.9 | |
| 3,001–10,000 | 5.6 | |
| 501–3,000 | 6.4 | |
| 0–500 | 0 | |
| Baseline ART adherence a and virologic suppression | ||
| Adherence to ART ≤25 years, % of cohort | Modeled cohort b | |
| Adherence >90% | 20 | |
| Adherence 81–90% | 14 | |
| Adherence 71–80% | 9 | |
| Adherence 61–70% | 7 | |
| Adherence ≤60% | 50 | |
| Adherence to ART >25 years, % of cohort | Modeled cohort b | |
| Adherence >90% | 34 | |
| Adherence 81–90% | 12 | |
| Adherence 71–80% | 6 | |
| Adherence 61–70% | 5 | |
| Adherence ≤60% | 43 | |
| ART efficacy (VL <50 copies/mL at 48 weeks) c, % | ||
| >95% adherence | 96.4 | [25–28] |
| <57% adherence | 0 | [29] |
| Late virologic failure, range by adherence level, monthly probability, % | 0.2-18 | [30–32] |
| Loss to follow-up | ||
| Loss to follow-up after 12 months, range by adherence level, monthly probability | 0.7-2 | [21,33–35] |
| Returning to care, monthly probability | 0.015 | [36] |
| Opportunistic infections off ART, range by CD4 count, monthly probability d | [70] | |
| Pneumocystis pneumonia | 0.0004-0.0084 | |
| Mycobacterium avium complex | 0.0001-0.0047 | |
| Toxoplasmosis | 0.0001-0.0007 | |
| Cytomegalovirus | 0.0001-0.0082 | |
| Fungal infection | 0.0001-0.0032 | |
| Other opportunistic infection | 0.0006-0.0116 | |
| Chronic AIDS death off ART, range by OI history, monthly probability e | [70] | |
| CD4 >500 | 0.00025 | |
| CD4 351-500 | 0.00583 | |
| CD4 201-350 | 0.00092-0.02696 | |
| CD4 101-200 | 0.00250-0.03303 | |
| CD4 51-100 | 0.00341-0.03254 | |
| CD4 0-50 | 0.01472-0.06900 | |
| Non-HIV-related death, by age, monthly probability | [71,72] | |
| 13-14 years | 0.00001-0.00002 | |
| 15-19 | 0.00002-0.00004 | |
| 20-24 | 0.00003-0.00006 | |
| 25-29 | 0.00004-0.00007 | |
| 30-39 | 0.00005-0.00012 | |
| 40-49 | 0.00011-0.00025 | |
| 50-59 | 0.00027-0.00068 | |
| 60-69 | 0.00071-0.00175 | |
| 70-79 | 0.00181-0.00416 | |
| 80-99 | 0.00433-0.01320 | |
| HIV Transmissions | ||
| HIV Transmissions, range by VL, per 100PY | [20,37,38] | |
| >100,000 copies/mL | 16.5 | |
| 10,001-100,000 | 14.8 | |
| 3,001-10,000 | 7.6 | |
| 501-3,000 | 3.8 | |
| 21-500 | 0.3 | |
| 0-20 | 0 | |
| Costs (USD 2018) | ||
| Adherence intervention, monthly | 100 | Modeled intervention |
| Routine care, range by CD4 cell count, monthly f | 260-1,150 | [40–42] |
| Opportunistic infection | 7,100-16,700 | [40–42] |
| ART, monthly | 2,670 | [43] |
a
Adherence is measured as percent of pills taken.
b
See Supplemental Methods for details.
c
Efficacy between 57% and 95% adherence is exponentially interpolated (Supplemental Methods).
f
Higher CD4 counts are associated with higher routine care costs.
SD: standard deviation; HVL: HIV viral load (HIV RNA); ART: antiretroviral therapy; VS: virologic suppression; USD: United States dollars; PY: person-years
Additional details of inputs may be found in the Supplemental Methods.