Table 1:
Parameter Values
| Parameter | Base Case Value (Range)* | Ref. | Parameter | Base Case Value (Range)* | Ref. | |
|---|---|---|---|---|---|---|
| Transmission & Mortality Parameters | Assay Characteristic Parameters | |||||
| Probability of HIV Transmission | SoC Sensitivity and Specificity | 100% | Model Assumption | |||
| Among Infants First Tested at 6 Weeks (PMTCT) | 0.022 (0.005–0.04) | [23–25] | PoC Sensitivity/ Specificity | |||
| Among Infants First Tested at 6 Weeks (no PMTCT) | 0.2 (0.1–0.3) | [23, 25, 26] | m-PIMA | 98% (96–100%) / 99.9% (99.8–99.9%) | [13] | |
| New Transmission Between 6 Weeks and 9 Months | 0.017 (0.005–0.03) | [23, 27] | GeneXpert IV & Edge | 96% (93–99%) / 99.8% (99.7–99.9%) | [13] | |
| Among Infants First Tested at 9 Months (PMTCT) | 0.09 (0.04–0.14) | [23–25] | Economic Parameters | |||
| Among Infants First Tested at 9 Months (no PMTCT) | 0.3 (0.15–0.45) | [23, 25, 26] | 9-Month Capital Cost per Instrument (x1000 USD 2018)** | |||
| Probability of HIV-Related Mortality (Untreated) | SoC | $35 ($32-$38) | CHAI, see Supplement | |||
| Between 6 Weeks and 9 Months (Infected by 6 Weeks) | 0.23 (0.18–0.28) | [3] | m-PIMA | $4.8 ($4.4-$5.3) | CHAI, see Supplement | |
| Between 6 Weeks and 18 Months (Infected by 6 Weeks) | 0.39 (0.34–0.44) | [3] | GeneXpert IV | $5.2 ($4.7-$5.8) | CHAI, see Supplement | |
| Between 6 Weeks and 18 Months (Infected after 6 Weeks and Lost to Follow-Up) | 0.30 (0.25–0.35) | [3] | GeneXpert Edge | $1.8 ($1.6-$2.0) | CHAI, see Supplement | |
| Between 9 Months and 18 Months (Infected by 9 Months) | 0.16 (0.11–0.21) | [3] | Recurrent Costs per Test (USD 2018) | |||
| Testing and Treatment Parameters | SoC | $15 (14–16) | CHAI, see Supplement | |||
| Proportion Tested at 6 Weeks | 0.85 (0.83–0.87) | [28] | m-PIMA | $25 ($23-$27) | CHAI, see Supplement | |
| Proportion Returning at 9 Months (HIV-Negative at 6 Weeks) | 0.8 (0.7–0.9) | [23] | GeneXpert IV & Edge | $20 ($18-$22) | CHAI, see Supplement | |
| Proportion Returning after 1 Week for Tiebreaker (PoC-Only Algorithm) | 0.95 (0.3–0.97) | Model Assumption | Number of SoC Devices | |||
| PMTCT Coverage | SoC | 5 (4–6) | CHAI, see Supplement | |||
| High | 93% (84–100%) | [14] | PoC+SoC | 1 | Model Assumption | |
| Low | 48% (43–53%) | [14] | Proportion EID of All SoC Tests | |||
| Probability of Ever Initiating ART (by 18 Months of Age) | SoC | 0.50 (0.45–0.55) | CHAI, see Supplement | |||
| After Positive SoC PCR Test | 0.48 (0.43–0.53) | [10, 11] | PoC+SoC | 0.025 (0.023–0.027) | CHAI, see Supplement | |
| After Positive PoC Test | 0.95 (0.85–1) | [10, 11] | Number of PoC Devices | 150 (140–160) | CHAI, see Supplement | |
| Probability of Initiating ART within 60 Days | Proportion EID of all PoC Tests (Integrated Capital Costs) | |||||
| After Positive SoC PCR Test | 0.20 (0.13–0.27) | [10, 11] | m-PIMA | 25% | [16] | |
| After Positive PoC Test | 0.89 (0.85–0.94) | [10, 11] | GeneXpert IV & Edge | 15% | [16] | |
*
All values were sampled uniformly across the specified ranges
**
Nine-month capital costs were calculated by dividing lifetime capital costs by the estimated instrument lifetime and multiplying by 9 months (the duration of the testing period for a given infant). See Supplementary Methods (SDC 1) for further details.