Table 5. Multivariate analysis using polytomous logistic regression model for factors associated with QFT-IT-negative and -indeterminate results (n = 503).
| QFT-IT-negative results | QFT-IT-indeterminate results | ||||||
| Proportion (%) | OR* | 95% CI | Proportion (%) | OR* | 95% CI | ||
| Age (years) | 1.04 | 1.01–1.07 | 1.04 | 0.97–1.11 | |||
| BMI | 18.5–24.9 | 4/217 (1.8) | 1.00 | 3/217 (1.4) | 1.00 | ||
| <16.0 | 9/77 (11.7) | 5.42 | 1.48–19.79 | 3/77 (3.9) | 1.82 | 0.29–11.18 | |
| 16.0–18.5 | 11/206 (5.3) | 2.65 | 0.79–8.85 | 9/206 (4.4) | 1.92 | 0.43–8.48 | |
| ≥25.0 | 0/3 (0.0) | NA | NA | 0/3 (0.0) | NA | NA | |
| HIV status | Negative | 19/459 (4.1) | 1.00 | 3/459 (0.7) | 1.00 | ||
| Positive | 5/44 (11.4) | 6.38 | 1.78–22.92 | 12/44 (27.3) | 99.59 | 15.85–625.61 | |
| HLA-DRB1*0701 (the number of alleles) | 5.09† | 2.31–11.22 | 4.25† | 1.27–14.16 | |||
QFT-IT: QuantiFERON-TB Gold In-Tube; BMI: Body mass index; HIV: human immunodeficiency virus; CI: Confidence interval; NA: Not available
*OR: Multinomial odds ratio, also known as relative risk ratio, that is obtained by exponentiating the logit coefficient.
†
OR per unit change in the number of alleles: Distribution of QFT-IT results and the number of HLA-DRB1*0701 alleles was shown in the text.