Table 4. Clinical factors associated with a boosted TST reaction.
| Characteristics | Boosted reaction | OR (95% CI) | P | |
| Absence | Presence | |||
| Subjects | 477 (85.8) | 79 (14.2) | ||
| Age (yrs) | 25 (21–47) | 26 (20–54) | ||
| 20–24 | 170 (35.6) | 17 (21.5) | 1.00 | |
| 25–29 | 218 (45.7) | 38 (48.1) | 1.63 (0.72–3.70) | 0.244 |
| 30–34 | 66 (13.8) | 16 (20.3) | 2.30 (0.85–6.26) | 0.103 |
| 35–39 | 14 (2.9) | 6 (7.6) | 1.63 (0.22–11.98) | 0.630 |
| >40 | 9 (1.9) | 2 (2.5) | – | 0.99 |
| Gender; male, n (%) | 135 (28.3) | 33 (41.8) | 1.47 (0.63–3.45) | 0.372 |
| BMI (median, IQR) | 20.0 (18.9–22.1) | 21.7 (19.8–22.7) | 1.16 (0.99–1.36) | 0.060 |
| Rejoined | 19 (4.0) | 3 (3.8) | 0.23 (0.02–2.26) | 0.207 |
| Previous TB history | 0 (0) | 0 (0) | – | – |
| Previously healed TB on CXR* | 18 (3.8) | 6 (7.6) | 1.65 (0.40–6.74) | 0.485 |
| TST induration (median, IQR), mm | 0 (0–3) | 6 (0–8) | ||
| 0 mm | 331 (69.4) | 25 (31.6) | 1.00 | |
| 1–4 mm | 45 (9.4) | 6 (7.6) | 2.53 (0.83–7.75) | 0.103 |
| 5–9 mm | 101 (21.2) | 48 (60.8) | 6.51 (3.13–13.53) | <0.001 |
| Job category | ||||
| Doctor | 129 (27.0) | 17 (21.5) | ||
| Nurse | 121 (25.4) | 17 (21.5) | ||
| Technician$ | 90 (18.9) | 14 (17.7) | ||
| Others | 137 (28.7) | 31 (39.2) | ||
| Interval between 1st and 2nd TST days(median, range) | 9 (4–65) | 10 (7–35) | ||
TST, tuberculin skin test; OR, odds ratio; CI, confidence interval; BMI, body mass index; IQR, interquartile range; TB, tuberculosis; CXR, simple chest radiography.
*
Data could not be obtained for one participant.
$
Technicians were defined as technical employees performing radiologic, laboratory, pathologic, and physiotherapeutic services.