Univariate and multivariate ORs of relationships between risk factors and M tuberculosis infection as determined by ELISpot and TST among household contacts of index cases
| Characteristic | Category | ELISpot | TST | Multivariate OR (95% CI) | |
| Univariate OR (95% CI) | Multivariate OR (95% CI) | Univariate OR (95% CI) | |||
| All contacts* n=175 | |||||
| Age | 1.05 (1.02 to 1.07) | 1.05 (1.02 to 1.09) | 0.98 (0.95 to 1.00) | 0.99 (0.96 to 1.03) | |
| Sex | Female | 1 | 1 | 1 | 1 |
| Male | 0.83 (0.42 to 1.63) | 0.97 (0.44 to 2.14) | 3.10 (1.28 to 7.48) | 1.91 (0.72 to 5.05) | |
| Smear and culture status of index case | Smear negative, culture negative | 1 | 1 | 1 | 1 |
| Smear negative, culture positive | 0.79 (0.30 to 2.10) | 0.73 (0.25 to 2.07) | 1.41 (0.58 to 3.45) | 1.36 (0.50 to 3.68) | |
| Smear positive, culture positive | 2.56 (1.25 to 5.26) | 2.40 (1.12 to 5.14) | 3.69 (1.67 to 8.17) | 4.41 (1.82 to 10.67) | |
| HIV status of contacts | Negative | 1 | 1 | 1 | 1 |
| Positive | 1.05 (0.52 to 2.13) | 0.70 (0.30 to 1.62) | 0.24 (0.12 to 0.49) | 0.25 (0.10 to 0.60) | |
| HIV status of index cases | Negative | 1 | 1 | 1 | 1 |
| Positive | 0.60 (0.30 to 1.17) | 0.61 (0.28 to 1.31) | 0.66 (0.30 to 1.47) | 1.10 (0.44 to 2.75) | |
| HIV-positive contacts† n=44 | |||||
| Smear and culture status of index case | Smear negative, culture negative | 1 | 1 | 1 | 1 |
| Smear negative, culture positive | 1.6 (0.20 to 12.69) | 1.87 (0.22 to 16.16) | 1.5 (0.24 to 9.46) | 1.09 (0.13 to 9.42) | |
| Smear positive, culture positive | 4.8 (1.05 to 21.91) | 5.36 (1.11 to 25.93) | 3.5 (0.88 to 13.93) | 3.43 (0.76 to 15.52) | |
↵* 47 contacts exposed to the 25 index cases that did not have both a smear and culture taken have been excluded from this analysis.
↵† 11/47 contacts exposed to the 25 index cases that did not have both a smear and culture taken and excluded from this analysis were HIV positive.
ELISpot, enzyme-linked immunospot; TST, tuberculin skin testing.