Table 3. Potential independent factors associated with QFT positivity of the study population.
| Variables | n/N(%) | p for χ2 test | Adjusted OR* (95% CI) |
|---|---|---|---|
| Study site | <0.0001 | ||
| Site A | 1052/5014(20.98) | Reference | |
| Site B | 801/4141(19.34) | 1.05(0.94–1.17) | |
| Site C | 1173/4213(27.84) | 1.39(1.26–1.54) | |
| Site D | 847/3896(21.74) | 1.31(1.17–1.46) | |
| Gender | <0.0001 | ||
| Female | 1793/9415(19.04) | Reference | |
| Male | 2080/7849(26.50) | 1.30(1.17–1.44) | |
| Age (years) | <0.0001 | ||
| 18–29 | 194/2344(8.28) | Reference | |
| 30–39 | 313/2116(14.79) | 1.84(1.51–2.25) | |
| 40–49 | 876/4513(19.41) | 2.50(2.10–2.97) | |
| 50–59 | 934/3479(26.85) | 3.85(3.24–4.59) | |
| 60–69 | 966/3047(31.70) | 4.93(4.14–5.86) | |
| ≥70 | 590/1765(33.43) | 5.60(4.65–6.74) | |
| Smoking status | <0.0001 | ||
| Never smoked | 2405/12176(19.75) | Reference | |
| Ever smoked | 1468/5086(28.86) | 1.28(1.15–1.43) | |
| History of close contact with TB patients | <0.0001 | ||
| No | 3480/15826(21.99) | Reference | |
| Yes | 221/708(31.21) | 1.38(1.16–1.65) | |
| LDL levela | <0.0001 | ||
| Normal | 3117/14538(21.44) | Reference | |
| Higher than normal | 754/2721(27.71) | 1.14(1.02–1.27) | |
| BMI (kg/m2) | 0.0028 | ||
| <18.5 | 168/908(18.50) | 0.89(0.76–1.03) | |
| 18.5–24.0 | 1987/9046(21.97) | Reference | |
| 24.0–28.0 | 1254/5350(23.44) | 1.09(0.99–1.18) | |
| ≥28.0 | 464/1960(23.67) | 1.17(1.04–1.33) |
Abbreviations: BMI = body mass index. CI = confidence interval. LDL = low density lipoprotein. OR = odds ratio. QFT = QuantiFERON-TB Gold In-Tube. TB = tuberculosis.
*Controlling for study site, age, gender, smoking status, LDL level, history of close contact with TB, and BMI when appropriated.
aRange of normal value in different study sites: Site A = 0–4.11 mmol/L, Site B = 0–3.36 mmol/L, Site C = 0–3.12 mmol/L, Site D = <3.1 mmol/L.