Table 3.
Adjusted risk ratios for QFT conversion (IFN-γ ≥ 0.70 IU/mL) at 18 months based on multivariable Poisson regression models with robust variance; Tijuana, Mexico, 2006–2008.
| Variable | Risk Ratio (95% Confidence Interval) | ||
|---|---|---|---|
| Bivariate Model | Reduced Model | Final Model | |
| Number of cigarettes smoked daily (quartiles) | |||
| 0–5 | 1.00 | 1.00 | 1.00 |
| 6–10 | 0.75 (0.37–1.55) | 1.04 (0.53–2.04) | 0.86 (0.46–1.63) |
| 11–15 | 0.53 (0.23–1.20) | 0.73 (0.36–1.51) | 0.54 (0.25–1.17) |
| ≥16 | 0.59 (0.24–1.43) | 0.79 (0.34–1.83) | 0.74 (0.33–1.64) |
| Education | |||
| High school or higher | 1.00 | 1.00 | |
| Less than high school | 2.83 (1.08–7.42) | 2.60 (0.96–7.03) | |
| Age | |||
| +10 years | 1.25 (0.80–1.94) | ||
| Gender | |||
| Male | 1.00 | ||
| Female | 0.81 (0.34–1.93) | ||
| Alcohol use | |||
| <2x per week | 1.00 | ||
| ≥2x per week | 1.04 (0.52–2.08) | ||
IFN-γ: interferon-gamma; QFT: QuantiFERON-TB Gold In-Tube.