Table 6.
Subject characteristics associated with CXR and TST discordance.
| Characteristic | N | CXR positive but TST negative | CXR negative but TST positive | ||
|---|---|---|---|---|---|
| n | aOR* (95% CI) | n | aOR* (95% CI) | ||
| Total | 1163** | 79 | 501 | ||
| Age group in years | |||||
| 18–20 yrs | 130 | 6 (4.6%) | 1.0 | 42 (32.3%) | 1.0 |
| 21–30 yrs | 270 | 3 (1.1%) | 0.23 (0.06–0.94) | 120 (44.4%) | 1.90 (1.22–2.98) |
| 31–40 yrs | 279 | 7 (2.5%) | 0.53 (0.17–1.59) | 161 (57.7%) | 2.91 (1.87–4.53) |
| 41–50 yrs | 252 | 19 (7.5%) | 1.59 (0.62–4.11) | 103 (40.9%) | 1.54 (0.98–2.42) |
| 51–64 yrs | 189 | 32 (16.9%) | 3.88 (1.57–9.62) | 69 (36.5%) | 1.38 (0.85–2.25) |
| ≥65 yrs | 43 | 12 (27.9%) | 6.76 (2.31–19.79) | 6 (14.0%) | 0.39 (0.15–1.004) |
| Sex | |||||
| Female | 781 | 51 (6.5%) | 324 (41.5%) | 1.0 | |
| Male | 382 | 28 (7.3%) | N.S. and NIM | 177 (46.3%) | 1.33 (1.03–1.73) |
| Other major medical conditions | |||||
| No | 1146 | 72 (6.3%) | 1.0 | 497 (43.4%) | |
| Yes | 17 | 7 (41.2%) | 4.52 (1.58–12.96) | 4 (23.5%) | N.S. and NIM |
| BCG status | |||||
| Not vaccinated | 684 | 58 (8.5%) | 253 (37.0%) | 1.0 | |
| Vaccinated | 479 | 21 (4.4%) | N.S. and NIM | 248 (51.8%) | 1.61 (1.25–2.07) |
| M. avium reactivity | |||||
| No | 812 | 58 (7.1%) | 369 (45.4%) | 1.0 | |
| Yes | 351 | 21 (6.0%) | N.S. and NIM | 132 (37.5%) | 0.71 (0.54–0.93) |
CXR: chest radiograph; TST: tuberculin skin test; n: number in subset of N; aOR: adjusted odd ratio; 95% CI: 95% confidence interval; N.S.: not significant; NIM: not in model; BCG: bacille Calmitte-Guérin; QFT: QuantiFERON-TB test.
*Multivariate models were created using factors with P values ≤0.2 in univariate analysis and <0.05 in stepwise logistic regression until the best fitting, parsimonious model was identified. Model fit was evaluated using the Hosmer-Lemeshow test. Bold font indicates statistically significant adjusted odds ratios (aORs).
**Data from 83 subjects with indeterminate QFT-G results were excluded from analysis.