Risk factors for M tuberculosis infection
| TST ⩾10 mm | Total | % TST ⩾10 mm | Odds ratio | ||
|---|---|---|---|---|---|
| Unadjusted (95% CI) | Adjusted* (95% CI)n = 2328 | ||||
| *Adjusted for pack-years, age, sex, and taking into account possible clustering at address level. | |||||
| †R6.50 = US$1.00. | |||||
| Smoking (pack-years) | |||||
| Never smoked | 769 | 1102 | 70 | 1 | 1 |
| <5 | 443 | 550 | 81 | 1.86 (1.42 to 2.43) | 1.77 (1.33 to 2.35) |
| 5–15 | 343 | 407 | 84 | 2.39 (1.74 to 3.29) | 1.77 (1.25 to 2.50) |
| ⩾15 | 236 | 288 | 82 | 2.00 (1.40 to 2.84) | 1.90 (1.28 to 2.81) |
| Unknown | 41 | 54 | 76 | ||
| Sex | |||||
| Female | 1100 | 1477 | 74 | 1 | 1 |
| Male | 731 | 923 | 79 | 1.34 (1.08 to 1.65) | 1.24 (0.99 to 1.56) |
| Unknown | 1 | 1 | 100 | ||
| Age (years) | |||||
| 15–24 | 432 | 651 | 66 | 1 | 1 |
| 25–34 | 444 | 498 | 89 | 4.47 (3.14 to 6.37) | 4.30 (3.00 to 6.17) |
| 35–44 | 412 | 484 | 85 | 3.16 (2.28 to 4.37) | 2.82 (2.00 to 3.99) |
| 45–54 | 263 | 330 | 80 | 2.11 (1.50 to 2.97) | 1.96 (1.35 to 2.85) |
| ⩾55 | 264 | 408 | 65 | 0.88 (0.66 to 1.18) | 0.88 (0.64 to 1.22) |
| Unknown | 17 | 30 | 57 | ||
| Income (Rands)† | |||||
| <500 | 804 | 1088 | 74 | 1 | |
| 500–1999 | 685 | 893 | 77 | 1.18 (0.94 to 1.48) | |
| ⩾2000 | 315 | 381 | 83 | 1.93 (1.38 to 2.68) | |
| Unknown | 28 | 39 | 72 | ||
| Total | 1832 | 2401 | |||