Agreement and discordance between tuberculin skin test (TST) reactions and interferon-γ release assays (IGRAs) at baseline
| TST ⩾5 mm | TST ⩾10 mm | TST ⩾15 mm | |
| QFT-GIT (n=482) | |||
| Positive TST and positive IGRA | 307 (66) | 293 (61) | 257 (53) |
| Negative TST and negative IGRA | 39 (7) | 53 (19) | 77 (16) |
| Positive TST and Negative IGRA | 126 (26) | 112 (23) | 88 (18) |
| Negative TST and positive IGRA | 10 (2) | 24 (5) | 60 (12) |
| Agreement % | 71.8 | 71.8 | 69.3 |
| Kappa (95% CI) | 0.25 (0.18–0.31) | 0.28 (0.20–0.36) | 0.29 (0.20–0.37) |
| T-SPOT.TB (n=450) | |||
| Positive TST and positive IGRA | 259 (58) | 249 (55) | 221 (49) |
| Negative TST and negative IGRA | 40 (9) | 55 (12) | 84 (19) |
| Positive TST and Negative IGRA | 141 (31) | 126 (28) | 97 (22) |
| Negative TST and positive IGRA | 10 (2) | 20 (4) | 48 (11) |
| Agreement % | 66.4 | 67.8 | 67.8 |
| Kappa (95% CI) | 0.21 (0.14–0.28) | 0.25 (0.16–0.33) | 0.30 (0.21–0.39) |
Data are presented as n (%), unless otherwise stated. QFT-GIT: QuantiFERON-TB Gold-In-Tube.