Estimates of the probability of events in the model
| Probability % (range) | Reference | |||
|---|---|---|---|---|
| Prevalence of Mycobacterium tuberculosis infection in child household TB contacts | 0–2-year-old cohort: 28 (8–48) | 19–21 | ||
| 3–5-year-old cohort: 40 (23–62) | ||||
| Probability of test positivity in the study setting | 0–2 years—TST: 31.2 (22.2–41.5), TSPOT: 32.6 (23.2–43.2), QTF: 33.7 (24.0–44.5) | 22 * | ||
| 3–5 years—TST: 39.8 (29.8–50.5), TSPOT: 39.1 (28.8–50.0), QTF: 43.0 (32.4–54.2) | ||||
| TST† | 23 | |||
| Sensitivity‡ | 84 (75–93) | |||
| Specificity‡ | 88 (62–100) | |||
| Sensitivity in LMIC | 70 (45–94) | |||
| Specificity in LMIC | 93 (77–100) | |||
| QTF assays | 23 | |||
| Sensitivity‡ | 83 (75–92) | |||
| Specificity‡ | 91 (78–100) | |||
| Sensitivity in LMIC | 58 (28–87) | |||
| Specificity in LMIC | 94 (71–100) | |||
| T-SPOT | 23 | |||
| Sensitivity‡ | 84 (63–100) | |||
| Specificity‡ | 94 (87–100) | |||
| Sensitivity in LMIC | 77 (23–100) | |||
| Specificity in LMIC | 93 (83–100) | |||
| Child referred for IPT (referral) | 75 | 12,24 | ||
| Child begins IPT (uptake) | 75 | 12,24 | ||
| Child completes IPT (adherence) | 24 (10–80) | 10,12,24,25 | ||
| IPT treatment efficacy | 70 (50–90) | 5–8,26,27 | ||
| Development of disease given M tuberculosis infection in the absence of IPT | Age | Pulmonary | Disseminated | 1 |
| <2 | 35 (30–40) | 15 (10–20) | ||
| 2 | 15 (10–20) | 3.5 (2–5) | ||
| 3–5 | 5 (5–5) | 0.5 (0.5–0.5) | ||
| 6–10 | 2 (2–2) | 0.25 (0.25–0.25) | ||
| >10 | 15 (10–20) | 0.25 (0.25–0.25) | ||
| Development of death given active TB disease | Age | Pulmonary | Disseminated | 13,28,29 |
| <3 | 5 (2–8) | 10 (5–15) | ||
| 3–5 | 1 (0.5–2) | 4 (2–6) | ||
| >6 | 0.5 (0.2–0.7) | 2 (1–3) | ||
| ARI | 4 (2–6) | 30 | ||
| Dying from other causes | South African 2003 life tables | 31 | ||
↵* Data derived from study employing the Quantiferon-Gold In-tube version of QFN.
↵† Data derived from studies considering a TST to be positive if induration was ≥10 mm.
↵‡ Pediatric specific data from high, middle and low income countries used for base-case model.
ARI, annual risk of infection; IPT, isoniazid preventive therapy; LMIC, low middle income country (as defined by the World Bank Index); QTF, QuantiFERON; TB, tuberculosis; TSPOT, T-SPOT.TB; TST, tuberculin skin test.