Table 3. Univariate and multivariate analyses of baseline characteristics associated with incident tuberculosis (TB) infection.
| Person-years | Univariate HR (95% CI) | p value | Multivariate HR (95% CI) | p value | |
|---|---|---|---|---|---|
| Household Contacts Characteristics | |||||
| Age Categories | 3459 | ||||
| < 5 years | 0.25 (0.21–0.31) | <0.001 | 0.26 (0.20–0.33) | <0.001 | |
| 5 to 11 years | 0.31 (0.26–0.38) | <0.001 | 0.33 (0.26–0.42) | <0.001 | |
| 12 to 19 years | 0.37 (0.30–0.45) | <0.001 | 0.39 (0.30–0.49) | <0.001 | |
| 20 to 49 years | 0.89 (0.76–1.04) | 0.13 | 0.86 (0.73–1.02) | 0.09 | |
| ≥50 years | Reference | Reference | |||
| Male | 3459 | 0.90 (0.82–1.00) | 0.06 | 1.07 (0.96–1.21) | 0.22 |
| Nutritional Status | 3459 | ||||
| Underweight | 0.60 (0.36–0.99) | 0.05 | 0.56 (0.31–1.02) | 0.06 | |
| Overweight | 1.71 (1.54–1.90) | <0.001 | 1.09 (0.95–1.24) | 0.21 | |
| Normal | Reference | Reference | |||
| Comorbid Diseasea | 3459 | 1.34 (1.18–1.51) | <0.001 | 0.91 (0.79–1.06) | 0.2 |
| Number of BCG Scars | 3459 | ||||
| 0 | Reference | Reference | |||
| 1 | 1.51 (1.28–1.79) | <0.001 | 1.41 (1.17–1.69) | <0.001 | |
| 2 | 3.00 (2.46–3.65) | <0.001 | 1.71 (1.37–2.14) | <0.001 | |
| > 2 | 3.11 (2.31–4.18) | <0.001 | 1.65 (1.19–2.29) | 0.003 | |
| Isoniazid Preventive Therapy | 3459 | 0.50 (0.44–0.57) | <0.001 | NAb | |
| Heavy Alcohol Use | 3408 | 1.59 (1.24–2.02) | <0.001 | 0.91 (0.70–1.19) | 0.50 |
| Tobacco use | 3436 | 1.77 (1.41–2.21) | <0.001 | 1.15 (0.89–1.49) | 0.28 |
| HIV Positive | 3422 | 0.67 (0.21–2.21) | 0.52 | 0.49 (0.14–1.65) | 0.25 |
| Socioeconomic Status | 3394 | ||||
| Middle | Reference | Reference | |||
| Low | 1.00 (0.87–1.15) | 0.98 | 1.01 (0.87–1.18) | 0.89 | |
| High | 1.30 (1.11–1.52) | 0.001 | 1.12 (0.95–1.33) | 0.18 | |
| Self-Reported Diabetes Mellitus | 3441 | 1.74 (1.18–2.55) | 0.005 | 0.83 (0.52–1.33) | 0.44 |
| Index Case Characteristics | |||||
| HIV Positive | 3437 | 1.05 (0.73–1.50) | 0.80 | NA | |
| Smear Positive | 3459 | 1.26 (1.08–1.46) | 0.003 | 1.29 (1.09–1.52) | 0.003 |
| Cavitary Disease | 3417 | 1.39 (1.22–1.58) | <0.001 | 1.30 (1.13–1.51) | <0.001 |
| Tobacco use | 3390 | 0.80 (0.51–1.25) | 0.33 | NA | |
| Heavy Alcohol Use | 3334 | 1.15 (0.93–1.41) | 0.19 | 1.22 (0.97–1.52) | 0.09 |
BCG, Bacillus Calmette–Guérin; HR, Hazard Ratio.
a Comorbid disease includes any of the following: heart disease, high blood pressure, asthma, kidney disease, use of steroids or chemotherapy or immunosuppressant, any other self-reported chronic illness.
b Variable identified as a time-varying covariate.