23
Table 4: Risk Factors Associated with Discordance
*Variables
Total N
QFT-Positive/
TST-Negative n (%)†
Unadjusted RR (95% CI)
Adjusted RR‡ (95% CI)
TST-Positive/
QFT-Negative n (%)††
Unadjusted RR (95% CI)
Adjusted RR‡ (95% CI)
Number of children 2,396 31 (1.3) 553 (23.1)
Age Group
2–5 years old 6–9 years old 10–14 years old
493 678 1,225
1 (0.2) 5 (0.7) 25 (2.0)
1.0 3.64 (0.43, 31.0) 10.1 (1.37, 74.0)
1.0 3.56 (0.42, 30.4) 8.88 (1.20, 65.7)
89 (18.1) 151 (22.3) 313 (25.6)
1.0 1.23 (0.98, 1.56) 1.42 (1.15, 1.75)
1.0 1.28 (1.03, 1.60) 1.59 (1.31, 1.95) Sex
Male Female
1,251 1,145
17 (1.4) 14 (1.2)
1.0 0.90 (0.45, 1.82)
260 (20.8) 293 (25.6)
1.0 1.23 (0.70, 0.94)
1.0 1.19 (1.04, 1.36) Country of Exam
Mexico The Philippines Vietnam
923 900 573
20 (2.2) 8 (0.9) 3 (0.5)
1.0 0.41 (0.18, 0.93) 0.24 (0.07, 0.81)
1.0 0.46 (0.21, 1.05) 0.28 (0.08, 0.95)
58 (6.3) 354 (39.3) 141 (24.6)
1.0 6.26 (4.82, 8.13) 3.92 (2.94, 5.22)
1.0 6.16 (4.73, 8.02) 3.97 (2.97, 5.30) TB results in family members
Family member with culture-confirmed TB Family member was a TB suspect All family members with normal CXR**
67 273 2,056
1 (1.5) 2 (0.7) 28 (1.4)
1.10 (0.15, 7.94) 0.54 (0.13, 2.25)
1.0
28 (41.8) 101 (37.0) 424 (20.6)
2.03 (1.51, 2.72) 1.79 (1.50, 2.14)
1.0
1.36 (1.04, 1.79) 1.20 (1.02, 1.42)
1.0
*
To examine discordance, we removed children who were QFT+/TST+;
†After removing QFT+/TST+ children, QFT-positive children were compared to QFT-negative children (i.e. QFT+/TST- versus both QFT-/TST- and QFT-/TST+ children);
††After removing QFT+/TST+, TST-positive children were compared to TST-negative children (i.e. QFT-/TST+ versus both QFT-/TST- and QFT+/TST-children);
‡Adjusted models included age, sex, country of exam and the TB results of immigrating family members;
**
