Table 2.
Associations of Individual and Combined Risk Factors With Active Tuberculosis Risk: The Singapore Chinese Health Study
| HR (95% CI) | |||
|---|---|---|---|
| Cases/n | Model 1 | Model 2 | |
| Smoking status | |||
| Nonsmoking | 787/48 869 | 1.00 | 1.00 |
| Current smoking | 571/11 376 | 2.01 (1.78–2.26) | 1.96 (1.73–2.20) |
| BMI | |||
| ≥20.0 kg/m2 | 1036/51 329 | 1.00 | 1.00 |
| <20.0 kg/m2 | 322/8916 | 1.73 (1.53–1.97) | 1.67 (1.46–1.89) |
| Physical activitya | |||
| Active | 385/16 776 | 1.00 | 1.00 |
| Inactive | 973/43 469 | 1.15 (1.02–1.30) | 1.15 (1.02–1.30) |
| Alcohol consumption | |||
| Less than daily | 1258/58 215 | 1.00 | 1.00 |
| Daily drinking | 100/2030 | 1.36 (1.10–1.68) | 1.35 (1.09–1.66) |
| Diet qualityb | |||
| Hight diet quality | 879/44 343 | 1.00 | 1.00 |
| Low diet quality | 479/15 902 | 1.17 (1.05–1.31) | 1.17 (1.04–1.31) |
| Combined lifestyle factor score | |||
| 0 | 132/8872 | 1.00 | 1.00 |
| 1 | 441/28 465 | 1.24 (1.02–1.51) | 1.24 (1.02–1.51) |
| 2 | 464/16 736 | 1.86 (1.53–2.26) | 1.84 (1.51–2.23) |
| 3 | 225/5039 | 2.54 (2.05–3.16) | 2.52 (2.03–3.14) |
| 4 | 79/1026 | 4.08 (3.07–5.41) | 4.07 (3.07–5.41) |
| 5 | 17/107 | 9.39 (5.65–15.58) | 9.04 (5.44–15.02) |
| Ptrendc | <.0001 | <.0001 | |
The covariates in the model 1 included sex, age at recruitment, year of recruitment (1993–1995, 1996–1998), dialect group (Hokkien, Cantonese), level of education (no formal education, primary school, secondary school or higher), tea intake (none, monthly, weekly, daily), and total energy intake. In the analysis of individual risk factors, they were mutually adjusted in the model. Model 2 further adjusted for self-reported diabetes, hypertension, coronary heart disease, stroke, and cancer.
Abbreviations: BMI, body mass index; CI, confidence interval; HR, hazard ratio.
Physical activity was defined as moderate activity ≥2 hours/week or strenuous activity ≥0.5 hour/week; physical inactivity was defined as moderate activity <2 hours/week or strenuous activity <0.5 hour/week.
High diet quality was defined as at or above the median intake levels of either fish/shellfish or vegetables/fruits, or at or above the median intake levels of both; low diet quality was defined as below the median intake levels of both fish/shellfish and vegetables/fruits.
P trend was based on a test for linear trend using the combined risk factor score as an ordinal variable in the model.