Table 3 Risk factors for a positive tuberculin skin test (TST) for the 10 mm cut-off method and the 17 mm mirror method
Risk Factor | Tuberculin skin test > = 10 mm n = 4808 | Multivariate | Tuberculin skin test > = 17 mm n = 4808 | Multivariate | |||||
|---|---|---|---|---|---|---|---|---|---|
Negative | Positive | OR, 95% CI | OR, 95% CI | Negative | Positive | OR, 95% CI | OR, 95% CI | ||
Sex | Female | 1650 | 677/2327 (29.1%) | 1 | 2076 | 251/2327 (10.8%) | 1 | ||
Male | 1614 | 867/2481 (34.9%) | 1.3 (1.2,1.5) | 1.3 (1.2,1.5) | 2129 | 352/2481 (14.2%) | 1.4 (1.2,1.6) | 1.4 (1.2,1.7) | |
History of a house hold TB contact | Yes | 224 | 150/374 (40.1%) | 1.5 (1.2,1.8) | 1.5(1.2,1.8) | 119 | 19/138 (13.8%) | 1 | |
No | 3040 | 1394/4434 (31.4%) | 1 | 4086 | 584/4670 (12.5%) | 1.6 (1.2,2.1) | 1.6(1.2,2.1) | ||
Previous TB | Yes | 15 | 6/21 (28.6%) | 1 | 18 | 3/21 (14.3%) | 1 | ||
No | 3232 | 1528/4787 (32.1%) | 0.8 (0.3,2.1) | 4163 | 597/4760 (12.5%) | 1.2 (0.4,3.7) | |||
BCG Scar | Yes | 2623 | 1324/3947 (33.5%) | 1.3 (1.2,1.7) | 1.5 (1.3,1.8) | 3450 | 497/3947 (12.6%) | 1.0 (0.8,1.3) | 1.0 (0.8,1.3) |
No | 641 | 220/861 (25.6%) | 1 | 753 | 106/859 (12.3%) | 1 | |||
Residence | Urban | 189 | 69/258 (26.7%) | 1 | 231 | 27/258 (10.5%) | 1 | ||
Rural | 3075 | 1475/4550 (32.4%) | 1.2 (1.0,1.5) | 1.4 (1.1,1.9) | 3974 | 576/4550 (12.7%) | 1.2 (0.8,1.9) | 1.2(0.8,1.9) | |
School going | Yes | 3103 | 1415/4518 (31.3%) | 1 | 3960 | 558/4518 (12.4%) | 1 | ||
No | 161 | 129/290 (44.5%) | 1.8(1.4,2.2) | 1.8 (1.4,2.3) | 245 | 45/290 (15.5%) | 1.3 (0.9,1.8) | 1.3(1.0,1.8) | |
Orphaned | Yes | 1136 | 585/1721 (34.0%) | 1 | 1474 | 247/1721 (14.4%) | 1 | ||
No | 2128 | 959/3087 (31.1%) | 1.1 (1.0,1.3) | 1.1(1.0,1.3) | 2731 | 356/3087 (11.5%) | 1.3 (1.1,1.5) | 1.3(1.1,1.5) | |