Table 4.
Risk of tuberculosis (TB) in contacts tested with both the tuberculin skin test and an interferon-gamma release assay (all types). Tuberculin skin test considered positive if ≥10 mm
| Group comparison | No of studies | No of participants | Total (mean) person years follow-up | Active TB events (%)* | TB rate per 1000 person years (95% CI)† | Incidence rate ratio (95% CI)† | I2 (%) | |
|---|---|---|---|---|---|---|---|---|
| General population, TST positive‡ | 3 | 33 811 | 249 093 (7.4) | 55 (0.2) | 0.3 (0.1 to 1.1) | - | - | |
| Dual positive v dual negative | ||||||||
| IGRA positive and TST positive v IGRA negative and TST negative§ | 4 | 588 v 2724 | 1576 (2.7) v 5856 (2.1) | 36 (8.7) v 15 (0.6) | 30.6 (10.9 to 85.9) v 2.6 (1.2 to 5.6) | 19.1 (2.9 to 127.3) | 80 | |
| Dual positive v discordant (positive/negative) | ||||||||
| IGRA positive and TST positive v IGRA positive and TST negative¶ | 3 | 566 v 476 | 1464 (2.6) v 956 (2.0) | 34 (8.8) v 29 (3.3) | 37.3 (10.5 to 132.4) v 16.5 (3.7 to 74.8) | 3.0 (0.2 to 40.7) | 83 | |
| IGRA positive and TST positive v IGRA negative and TST positive** | 6 | 641 v 1428 | 1715 (2.7) v 4410 (3.1) | 47 (12.1) v 29 (1.8) | 43.1 (21.1 to 88.0) v 6.2 (2.4 to 15.9) | 7.6 (1.6 to 36.7) | 86 | |
| Discordant (positive/negative) v dual negative | ||||||||
| IGRA positive and TST negative v IGRA negative and TST negative†† | 3 | 476 v 2643 | 956 (2.0) v 5541 (2.1) | 29 (3.3) v 15 (0.7) | 16.5 (3.7 to 74.8) v 3.1 (1.4 to 6.6) | 5.1 (2.4 to 10.8) | 0 | |
| IGRA negative and TST positive v IGRA negative and TST negative‡‡ | 4 | 672 v 2724 | 1534 (2.3) v 5856 (2.1) | 18 (2.4) v 15 (0.6) | 9.1 (3.0 to 28.0) v 2.6 (1.2 to 5.6) | 3.6 (1.8 to 7.2) | 0 | |
TST=tuberculin skin test; IGRA=interferon-gamma release assay; N/A=not applicable.
Percentage represents pooled cumulative incidence estimated from random effects meta-analysis.
Pooled estimates using random effects meta-analysis.
Data provided for reference. Populations are from British Columbia and Saskatchewan, Canada, and Florida, USA.
One study used the T-SPOT.TB IGRA, whereas the remaining three used the QFT-GIT (QuantiFERON Gold-In-Tube) IGRA. One study, using QFT-GIT, was exclusively in contacts aged <18 years.
One study used the T-SPOT.TB IGRA, whereas the remaining two used the QFT-GIT IGRA. One study, using QFT-GIT, was exclusively in contacts aged <18 years.
One study used the T-SPOT.TB IGRA, whereas the remaining five used the QFT-GIT IGRA. Two studies, using QFT-GIT, were exclusively in contacts aged <18 years.
One study used the T-SPOT.TB IGRA, whereas the remaining two used the QFT-GIT IGRA. One study, using QFT-GIT, was exclusively in contacts aged <18 years.
One study used the T-SPOT.TB IGRA, whereas the remaining three used the QFT-GIT IGRA. One study, using QFT-GIT, was exclusively in contacts aged <18 years.