Table 4 Incidence rate QFT conversion at visit 2 and visit 3 using different definitions of conversion
|  | Definition 1 (< 0.35, increase 0.35) n = 439 negative at V1 | Definition 2 (< 0.2, ≥0.7) n = 374 negative at V1 | Definition 3 (< 0.2, ≥1.05) n = 374 negative at V1 | Definition 4 (< 0.2, ≥1.4) n = 374 negative at V1 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Incident events | Person years | Incident Rate (95%CI) | Incident events | Person years | Incident Rate (95%CI) | Incident events | Person years | Incident Rate (95%CI) | Incident events | Person years | Incident Rate (95%CI) | |
Both countries | ||||||||||||
 Total | 175 | 7.5 | 23.2 (20.0–26.9) | 114 | 6.8 | 16.7 (13.9–20.0) | 93 | 7.0 | 13.1 (10.7–16.1) | 79 | 7.2 | 10.9 (8.7–13.6) |
 End follow-up V1-V2 | 113 | 4.9 | 23.3 (19.3–27.9) | 72 | 4.2 | 17.0 (13.5–21.5) | 56 | 4.3 | 12.9 (9.9–16.8) | 46 | 4.4 | 10.4 (7.8–13.9) |
 End follow-up V2-V3 | 62 | 2.7 | 23.1 (18.0–29.6) | 42 | 2.6 | 16.1 (11.9–21.8) | 37 | 2.7 | 13.5 (9.8–18.6) | 33 | 2.8 | 11.6 (8.2–16.3) |
HIV status contact* | ||||||||||||
 HIV negative | 125 | 4.6 | 27.4 (22.9–32.6) | 78 | 4.1 | 19.0 (15.2–23.7) | 63 | 4.3 | 14.7 (11.5–18.8) | 53 | 4.4 | 12.0 (9.2–15.7) |
 HIV positive, no ARV | 42 | 2.7 | 15.8 (11.7–21.4) | 30 | 2.4 | 12.3 (8.6–17.6) | 24 | 2.5 | 9.7 (6.5–14.4) | 22 | 2.5 | 8.8 (5.8–13.3) |
 HIV positive & ARV | 6 | 0.3 | 20.2 (9.1–44.9) | 5 | 0.3 | 18.1 (7.5–43.4) | 5 | 0.3 | 17.3 (7.2–41.5) | 3 | 0.3 | 9.8 (3.2–30.5) |
Zambia | ||||||||||||
 Total | 131 | 5.2 | 25.1 (21.1–29.8) | 87 | 4.9 | 17.6 (14.3–21.7) | 72 | 5.1 | 14.0 (11.1–17.7) | 63 | 5.2 | 12.0 (9.4–15.4) |
 End follow-up V1-V2 | 77 | 3.1 | 25.1 (20.1–31.4) | 50 | 2.8 | 17.9 (13.6–23.7) | 38 | 2.9 | 13.3 (9.7–18.2) | 33 | 2.9 | 11.4 (8.1–16.1) |
 End follow-up V2-V3 | 54 | 2.1 | 25.0 (19.2–32.7) | 37 | 2.1 | 17.2 (12.4–23.7) | 34 | 2.3 | 15.0 (10.7–21.0) | 30 | 2.3 | 12.8 (8.9–18.3) |
HIV status contact* | ||||||||||||
 HIV negative | 93 | 3.0 | 30.7 (25.0–37.6) | 61 | 2.8 | 21.3 (16.6–27.4) | 50 | 2.9 | 16.7 (12.7–22.1) | 44 | 3.1 | 14.4 (10.7–19.3) |
 HIV positive, no ARV | 31 | 1.9 | 16.1 (11.3–22.9) | 20 | 1.9 | 10.7 (6.9–16.6) | 16 | 1.9 | 8.4 (5.1–13.7) | 15 | 1.9 | 7.8 (4.7–13.0) |
 HIV positive & ARV | 5 | 0.2 | 20.7 (8.6–49.7) | 5 | 0.2 | 24.6 (10.2–59.1) | 5 | 0.2 | 23.2 (9.6–55.7) | 3 | 0.2 | 12.9 (4.2–40.2) |
Region by TST prevalence | ||||||||||||
 Lusaka, high TST | 49 | 1.5 | 33.0 (24.9–43.7) | 31 | 1.4 | 21.9 (15.4–31.2) | 27 | 1.5 | 18.1 (12.4–26.4) | 24 | 1.5 | 15.7 (10.5–23.5) |
 Urban, high TST | 39 | 1.5 | 26.3 (19.2–35.9) | 27 | 1.4 | 19.5 (13.3–28.4) | 20 | 1.5 | 13.8 (8.9–21.4) | 18 | 1.5 | 12.2 (7.7–19.3) |
 Urban, low TST | 29 | 1.7 | 17.5 (12.2–25.2) | 20 | 1.6 | 12.8 (8.2–19.9) | 16 | 1.6 | 9.9 (6.1–16.3) | 13 | 1.6 | 7.9 (4.6–13.7) |
 Rural, low TST | 14 | 0.6 | 23.4 (13.9–39.5) | 9 | 0.6 | 15.3 (7.9–29.5) | 9 | 0.6 | 15.3 (7.9–29.5) | 8 | 0.6 | 13.4 (6.7–26.9) |
South Africa | ||||||||||||
 Total | 44 | 2.3 | 18.9 (14.1–25.5) | 27 | 1.9 | 14.3 (9.8–20.8) | 21 | 1.9 | 10.8 (7.0–16.5) | 16 | 2.0 | 7.9 (4.9–13.0) |
 End follow-up V1-V2 | 36 | 1.8 | 20.1 (14.5–27.8) | 22 | 1.4 | 15.3 (10.1–23.3) | 18 | 1.5 | 12.3 (7.7–19.5) | 13 | 1.5 | 8.6 (4.9–14.8) |
 End follow-up V2-V3 | 8 | 0.5 | 15.2 (7.6–30.5) | 5 | 0.5 | 10.9 (4.6–26.4) | 3 | 0.5 | 6.3 (2.0–19.5) | 3 | 0.5 | 6.0 (1.9–18.6) |
HIV status contact* | ||||||||||||
 HIV negative | 32 | 1.5 | 20.8 (14.7–29.4) | 17 | 1.2 | 13.6 (8.5–21.9) | 13 | 1.3 | 10.0 (5.8–17.3) | 9 | 1.4 | 6.7 (3.5–12.8) |
 HIV positive, no ARV | 11 | 0.7 | 15.2 (8.4–27.4) | 10 | 0.6 | 17.6 (9.5–32.8) | 8 | 0.6 | 13.6 (6.9–27.6) | 7 | 0.6 | 11.9 (5.7–25.1) |
 HIV positive & ARV | 1 | 0.1 | 17.9 (2.5–127.0) | 0 | 0.1 | N.A. | 0 | 0.1 | N.A. | 0 | 0.1 | N.A. |
TST prevalence | ||||||||||||
 High | 27 | 1.1 | 25.1 (17.2–36.7) | 15 | 0.9 | 16.9 (10.2–28.1) | 11 | 0.9 | 11.8 (6.6–21.4) | 9 | 0.9 | 9.3 (4.8–17.8) |
 Low | 17 | 1.2 | 13.6 (8.5–21.9) | 12 | 1.0 | 11.9 (6.8–21.0) | 10 | 1.0 | 9.8 (5.3–18.3) | 7 | 1.0 | 6.7 (3.2–14.0) |