Table 1.
Selected model input parameters (children aged 0–5 years).a
| Clinical Inputs | Value | Sources | |
| CD4+% at presentation to care, by age | [18] | ||
| 6 months (sensitivity analysis) | 25% | ||
| 12 months (base-case) | 22% | ||
| 24 and 35 months (sensitivity analyses) | 19% | ||
| ART efficacy: HIV-RNA <400 copies/ml at 24 weeks on ARTb | P1060 | PENPACT-1 | |
| First-line nevirapine strategy | |||
| Nevirapine (in first-line ART) | 75% | 77% | |
| Lopinavir/ritonavir (in second-line ART) | 75% | 81% | |
| (sensitivity analysis: 10–80%) | Derived from [8,9,28] | ||
| First-line lopinavir/ritonavir strategy | |||
| Lopinavir/ritonavir (in first-line ART) | 91% | 72% | |
| Nevirapine (in second-line ART) | 75% | 74% | |
| (Sensitivity analysis: 10–80%) | |||
| Darunavir-based regimen (sensitivity analysis) | 95% (assumption) | ||
| Risk of virologic failure after suppression (any ART) | 0.91% month (Sensitivity analysis: 0.5–3.6%) | Derived from [8,9,28] | |
| Loss to follow-up after ART initiation (% risk/month) | 0.2 (Sensitivity analysis: 0–0.8) | [31,32] | |
| Cost Inputsc | Cost (2012 USD) | Sources |
| Opportunistic infection care (per event; range by type of OI) | ||
| South Africa | $310–2490 | [24] |
| Côte d’Ivoire | $60–420 | [25] |
| Routine care (per month, range by CD4+%/CD4+)d | ||
| South Africa | $25–205 | [22,23] |
| Côte d’Ivoire | $30–40 | [25,26] |
| Care in the last month of life | ||
| South Africa | $800 | [22,23] |
| Côte d’Ivoire | $65 | [25,26] |
| Antiretroviral regimen costs (per month, range by age/weight)e | ||
| Lopinavir/ritonavir (liquid: age <3 years (base case) or <5 years (sensitivity analyses) | $17–27 (Sensitivity analysis: ↑1–15x) | [6,11] |
| Lopinavir/ritonavir (pediatric or adult tablets) | $13–29 | |
| Nevirapine (pediatric or adult tablets) | $3–8 | |
| Nevirapine/zidovudine/lamivudine (pediatric tablets, age <3 years) | $6–8 | |
| Abacavir/lamivudine (pediatric or adult tablets) | $8–18 | |
| Zidovudine/lamivudine (pediatric or adult tablets) | $4–9 | |
| Efavirenz (pediatric or adult tablets, age ≥3 years) | $3–7 | |
| Darunavir/ritonavir-based third-line ART (in sensitivity analyses only) | $36–92 |
aThis table includes selected inputs for children entering care at ages 0–35 months, which are applied until children reach 59 months of age. At age 60 months and beyond, separate sets of input data are applied. Complete inputs are shown in Appendix Table A for children aged below and at least 60 months.
bART efficacy: probability of suppressing HIV-RNA to below 400 copies/ml by 24 weeks (in base case analysis) or 48 weeks (in sensitivity analysis) after initiation of ART. Results from the PENPACT-1 trial are from a posthoc subgroup of children limited to those enrolling before 3 years of age and treated with nevirapine or lopinavir/ritonavir [8,9,28].
cIn sensitivity analyses, all costs were varied from 0.5–2.0 times the costs shown.
dRoutine clinical care costs include CD4+ and viral load monitoring, according to the modeled scenario.
eMonthly ART drug doses were calculated for children ages 0–13 years old based on the WHO weight-based dosing recommendations. Daily doses were then multiplied by unit drug costs from the May 2012 Clinton Health Access Initiative (CHAI) antiretroviral drug price list to determine monthly ART costs by age and weight. All children were assumed to receive liquid/syrup drug formulations until age 3 years for lopinavir/ritonavir (5 years in sensitivity analyses), and until age 6 months for all other medications, for which dispersible tablets are available. After these ages, children were assumed to transition to pediatric or adult tablet formulations based on weight-based dosing recommendations. Fixed-dose combinations were assumed to be used where available [11]. In the absence of data on darunavir/r costs for children, we assumed third-line ART would have costs equal to twice first-line lopinavir/r-based regimen costs.