Table 1. Model input parameters for analysis of immunological staging by POC-CD4 versus LAB-CD4 in Mozambique.
| Category | Variable | Base Case Value | Range (Minimum–Maximum) | Reference | |
| LAB-CD4 | POC-CD4 | ||||
| Cohort characteristics | Mean CD4 count, cells/µl (SD) | 300 (230) | Same | 50–800 | [14] |
| Mean age, years (SD) | 32.7 (10.1) | Same | 20–70 | [14] | |
| Female, percent | 65 | Same | 0–100 | [14] | |
| Immunological staging characteristics | Sensitivity, percent a | 100 | 90 | 85–100 | [36] |
| Specificity, percent a | 100 | 85 | 79–100 | [36] | |
| Overall linkage for cohort, percent | 34 | 61 | 10–100 | Adapted from [14] | |
| Test completion, percent | 53 | 83 | 10–100 | Adapted from [14] | |
| Results receipt, percent | 88 | 99 | 10–100 | Adapted from [14] | |
| Initiation of care for observed ART-eligible patients, percent | 63 | 68 | 10–100 | Adapted from [14] | |
| Initiation of care for observed ART-ineligible patients, percent | 81 | 79 | 10–100 | Adapted from [14] | |
| CD4 test cost, US dollars | 10 | 24 | 10–1,000 | [39],[40] | |
| Range of regional access to HIV care | Linkage after WHO stage 3 or 4 OI, percent | 75 | Same | 100, 50, 25 | Assumption |
| Linkage after TB, percent | 43 | Same | 65, 25, 13 | [33],[34] | |
| Frequency of routine HIV testing | Every 10 y | Same | Every 5 y, once, never | Assumption | |
| ART efficacy after treatment initiation | HIV RNA suppressed at 6 mo, overall percent b | 79 | Same | [29] | |
| Mean monthly CD4 increase on suppressed ART | |||||
| Initial 8 wk, cells/µl (SD) | 67 (17) | Same | [41] | ||
| Monthly increase after 8 wk, cells/µl (SD) | 3 (1) | Same | [41] | ||
| Loss to follow-up probability, monthly percent c | 0.2–1.1 | Same | 0–1.9 | Derived from [32],[43] | |
| Mean time spent LTFU, months (SD) a | 31 (27) | Same | 0–60 | [32] | |
| Mozambique national treatment policy | ART initiation criteria | ||||
| CD4 count, cells/µl | ≤250 | Same | [6] | ||
| OI (WHO stage 3 or 4) | Yes | Same | [6] | ||
| TB | Yes | Same | [6] | ||
| Available ART | |||||
| First-line ART | AZT + 3TC + NVP | Same | [6] | ||
| Second-line ART | AZT + 3TC + LPV/r | Same | [6] | ||
| Annual costs (US dollars) | Routine HIV care for patients with CD4 count ≤250/µl d | 250 | Same | 30–380 | Adapted from [46] |
| Routine HIV care for patients with CD4 count>250/µl d | 160 | Same | 20–230 | Adapted from [46] | |
| First-line ART regimen | 120 | Same | [50] | ||
| Second-line ART regimen | 500 | Same | [50] | ||
Model output using cited input parameters.
Overall suppression will be lower for second-line ART, as poorly adherent patients are more likely to experience ART failure and initiate second-line ART.
Loss to follow-up includes interruptions in HIV care of at least 12 mo among those HIV-infected patients who are already linked to care and excludes attrition from care due to mortality or transfers to another clinical care site.
Costs of routine HIV care on first-line ART include direct costs for inpatient and outpatient care related to HIV infection, co-trimoxazole prophylaxis, ART when initiated and any toxicity if it occurs, and laboratory CD4 tests for ongoing immunological monitoring. We exclude costs associated with absence from work or transport to clinics, as neither the MMOH nor other funding sources are responsible for such costs.
3TC, lamivudine; AZT, zidovudine; LPV/r, lopinavir/ritonavir; NVP, nevirapine.