Table 3. Risk factors for prevalent smear positive TB.
| Univariate | Multivariate analysis | |||
|---|---|---|---|---|
|
|
||||
| Variable | OR | OR | (95% CI) | Population attributable fraction |
| Age less than 25 | 1 | 1 | PT = 0.004 | |
| Age 25-34 | 4.90 | 3.72 | (1.45 to 9.54) | |
| Age 35-44 | 5.09 | 3.20 | (1.10 to 9.32) | |
| Age ≥ 45 | 0.93 | 0.68 | (0.13 to 3.64) | |
| Male | 2.09 | 3.13 | (1.53 to 6.40) | 40.0% |
| HIV−, no past TB | 1 | 1 | ||
| HIV+, no past TB a | 4.12 | 3.26 a | (1.59 to 6.67) | 30.0%a |
| HIV−, past TB | 10.85 | 7.57 | (2.10 to 27.41) | 6.6% |
| HIV+, past TB a | 4.21 | 2.45 a | (0.54 to 11.08) | 3.0%a |
| Household TB contacts | ||||
| None in last 2 yrs | 1 | 1 | PT = 0.34 | |
| 1 contact in last 2 yrs | 1.87 | 1.60 | (0.69 to 3.70) | 6.6% |
| ≥ 2 contacts in last 2 yrs | 2.76 | 2.54 | (0.59 to 10.98) | 3.1% |
| AUDIT score | 1.02 | 1.03 | (0.96 to 1.11) | |
| Smoking (per pack-year) | 1.04 | 1.03 | (0.97 to 1.10) | |
| Beer hall attendance | 0.91 | 0.19 | (0.04 to 0.82) | |
| Church attendance | 0.47 | 0.58 | (0.29 to 1.16) | |
| Crowding | ||||
| Less than 2 per room | 1 | 1 | PT = 0.038 | |
| 2 to 4 per room | 2.57 | 2.19 | (1.12 to 4.26) | 30.3% |
| ≥ 4 per room | 4.14 | 3.64 | (0.81 to 16.46) | 3.7% |
| No. of assets owned (per asset)b | 0.77 | ND | ||
a
HIV and past TB treatment were modeled as a combined categorical variable because of the significant effect-modification described in the results (p = 0.021). An otherwise similar multivariate model including 3 categories for HIV/past TB, not distinguishing HIV-infected participants on the basis of their past TB treatment history gave adjusted OR for HIV of 3.15 (95% CI 1.6 – 6.3) PAF 33%, as stated in the abstract.
b
See Methods for description of socioeconomic status variables. Omitted from multivariate analysis as no longer significant and with high number of missing data points