Annual incidence of latent tuberculosis (TB) infection (LTBI) measured by the tuberculin skin test (TST) and interferon-γ release assay (IGRA): differences by study quality
| Study description | All studies | High- and medium-quality studies | ||||
| Study data | Annual incidence pooled estimate (95% CI) % | Study data | Annual incidence pooled estimate (95% CI) % | |||
| Studies n | IQR for incidence estimate % | Studies n | IQR for incidence estimate % | |||
| Annual incidence of LTBI measured by TST | ||||||
| Overall | 15 | 4–21 | 10 (7–13) | 11 | 5–22 | 10 (7–13) |
| Stratified by type of participants | ||||||
| Healthcare workers | 8 | 10–23 | 17 (9–24) | 6 | 14–24 | 18 (9–27) |
| Physicians | 3 | 6–14 | 9 (0–18) | 1 | 11 (9–15) | |
| Nurses | 2 | 12–24 | 9 (6–12) | 0 | ||
| Allied health professionals | 3 | 11–22 | 15 (3–27) | 1 | 25 (16–37) | |
| General services# | 0 | 0 | ||||
| Healthcare students | 5 | 4–6 | 5 (3–6) | 4 | 4–6 | 5 (3–6) |
| Stratified by TB incidence per 100 000 | ||||||
| 0–24 | 3 | 3–4 | 3 (1–5) | 1 | 1 (0–4) | |
| 25–99 | 5 | 11–22 | 16 (9–22) | 4 | 19–23 | 19 (11–26) |
| 100–199 | 2 | 5–5 | 5 (4–6) | 2 | 5–5 | 5 (4–6) |
| 200–299 | 4 | 7–13 | 10 (2–19) | 3 | 5–10 | 7 (2–13) |
| ≥300 | 1 | 38 (24–55) | 1 | 38 (24–55) | ||
| Stratified by study quality | ||||||
| High | 3 | 5–15 | 7 (3–11) | 3 | 5–15 | 7 (3–11) |
| Medium | 8 | 7–21 | 11 (7–16) | 8 | 7–21 | 11 (7–16) |
| Low | 4 | 4–9 | 8 (1–16) | |||
| Annual incidence of LTBI measured by IGRA | ||||||
| Overall | 5 | 10–22 | 15 (10–21) | 5 | 10–22 | 15 (10–21) |
| Stratified by type of participants | ||||||
| Healthcare workers | 4 | 10–22 | 18 (10–26) | 4 | 10–22 | 18 (10–26) |
| Physicians | 1 | 19 (15–23) | 1 | 19 (15–23) | ||
| Nurses | 1 | 10 (8–13) | 1 | 10 (8–13) | ||
| Allied health professionals | 1 | 10 (6–15) | 1 | 10 (6–15) | ||
| General services# | 0 | 0 | ||||
| Healthcare students | 1 | 8 (5–12) | 1 | 8 (5–12) | ||
| Stratified by TB incidence per 100 000 | ||||||
| 0–24 | 0 | 0 | ||||
| 25–99 | 2 | 12–17 | 12 (10–14) | 2 | 12 (10–14) | |
| 100–199 | 1 | 30 (16–48) | 1 | 30 (16–48) | ||
| 200–299 | 1 | 8 (5–12) | 1 | 8 (5–12) | ||
| ≥300 | 1 | 22 (15–31) | 1 | 22 (15–31) | ||
| Stratified by study quality | ||||||
| High | 0 | 0 | ||||
| Medium | 5 | 10–22 | 15 (10–21) | 5 | 10–22 | 15 (10–21) |
| Low | 0 | |||||
| IGRA reversion rate (annual) | 5 | 7–21 | 17 (7–26) | 5 | 7–21 | 17 (7–26) |
#: general services included cleaners, drivers and housekeepers.