Table 2. Logistic regression modeling for Mycobacterium tuberculosis infection (positive IGRA) in household contacts ≥15 years of age*.
| Characteristic/Level | All HHCs ≥15 years of age | HHCs ≥15 years of age without previous TB treatment | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| n/N (%) 471/686 (69%) |
Univariable | Multivariable | n/N (%) 407/612 (67%) |
Univariable | Multivariable | ||||||
| Odds Ratio [95% CI] | P value | Odds Ratio [95% CI] | P value | Odds Ratio [95% CI] | P value | Odds Ratio [95% CI] | P value | ||||
| HHC’s Age | 15–24 years | 108/184 (59%) | 0.7 [0.4,1.0] | <0.001 | 0.7 [0.4, 1.0] | <0.001 | 100/175 (57%) | 0.7 [0.5, 1.1] | <0.001 | 0.6 [0.4, 1.0] | <0.001 |
| 25–49 years | 252/334 (75%) | 1.5 [1.0, 2.3] | 1.6 [1.0, 2.5] | 214/290 (74%) | 1.5 [1.0, 2.3] | 1.6 [1.0, 2.4] | |||||
| ≥50 years | 111/168 (66%) | 1.0 (ref) | 1.0 (ref) | 93/147 (63%) | 1.0 (ref) | 1.0 (ref) | |||||
| HHC’s Sex | Male | 162/250 (65%) | 0.8 [0.5, 1.0] | 0.10 | 137/223 (61%) | 0.8 [0.5, 1.0] | 0.10 | ||||
| Female | 309/436 (71%) | 1.0 (ref) | 270/389 (69%) | 1.0 (ref) | |||||||
| HHC’s HIV Status | HIV-positive | 36/56 (64%) | 0.8 [0.4, 1.5] | 0.43 | 0.5 [0.2, 0.9] | 0.12 | 25/43 (58%) | 0.6 [0.3, 1.3] | 0.18 | 0.4 [0.2, 0.9] | 0.11 |
| Unknown | 78/123 (63%) | 0.7 [0.5, 1.0] | 0.8 [0.5, 1.2] | 70/113 (62%) | 0.7 [0.5, 1.1] | 0.8 [0.5, 1.2] | |||||
| HIV-negative | 357/507 (70%) | 1.0 (ref) | 1.0 (ref) | 312/456 (68%) | 1.0 (ref) | 1.0 (ref) | |||||
| HHC’s History of COPD/ Asthma | Yes | 24/29 (83%) | 1.9 [0.8, 4.8] | 0.11 | 18/23 (78%) | 1.6 [0.6, 4.7] | 0.34 | ||||
| No | 442/643 (69%) | 1.0 (ref) | 385/577(67%) | 1.0 (ref) | |||||||
| HHC Used Alcohol Almost Every Day Sometime in Past 12 Mos. | Yes | 46/54 (85%) | 2.7 (1.2, 6.1) | 0.004 | 32/40 (80%) | 2.0 (0.9, 4.5) | 0.060 | ||||
| No | 419/625 (67%) | 1.0 (ref) | 370/566 (65%) | ||||||||
| HHC’s Smoking History | Current | 117/147 (80%) | 1.7 (1.2, 2.6) | 0.033 | 89/116 (77%) | 1.6 (1.0, 2.5) | 0.080 | ||||
| Previous | 36/52 (69%) | 1.2 (0.7, 2.0) | 25/40 (63%) | 0.9 (0.5, 1.7) | |||||||
| Never | 318/487 (65%) | 1.0 (ref) | 293/456 (64%) | 1.0 (ref) | |||||||
| HHC’s History of Previous TB Treatment | Yes | 64/74 (86%) | 2.6 [1.4, 4.7] | <0.001 | 2.1 [1.0, 4.2] | 0.049 | -- | ||||
| No/Unknown | 407/612 (67%) | 1.0 (ref) | 1.0 (ref) | 407/612 (67%) | |||||||
| HHC Incarceration, Substance and Alcohol Use Composite in Past 12 Mos.a | Incarcerated | 19/20 (95%) | 6.7 [1.9, 24.4] | <0.001 | 7.3 [1.5, 34.4] | <0.001 | 16/17 (94%) | 6.7 [1.6, 27.7] | <0.001 | 7.4 [1.4, 38.5] | <0.001 |
| Never Incarcerated, Used Substances and/or Alcohol | 67/80 (84%) | 2.3 [1.3, 4.2] | 2.6 [1.3, 5.5] | 48/60 (80%) | 2.0 [1.0, 3.9] | 2.6 [1.2, 5.5] | |||||
| Never Incarcerated, No Substances, No Alcohol Use | 380/578 (66%) | 1.0 (ref) | 1.0 (ref) | 339/528 (64%) | 1.0 (ref) | 1.0 (ref) | |||||
| Index Participant’s Sputum Smear | AFB-positive | 222/314 (71%) | 1.2 (0.8, 1.7) | 0.38 | 191/279 (68%) | 1.2 (0.8, 1.7) | 0.45 | ||||
| AFB-negative/ Unknown | 314/372 (67%) | 1.0 (ref) | 216/333 (65%) | 1.0 (ref) | |||||||
| Relationship of IP to HHC | Spouse | 37/59 (63%) | 0.8 [0.5, 1.5] | 0.64 | 33/55 (60%) | 0.8 [0.4, 1.5] | 0.54 | ||||
| Child | 86/123 (70%) | 1.1 [0.7, 1.7] | 71/103 (69%) | 1.2 [0.7, 1.9] | |||||||
| Mother | 36/54 (67%) | 0.9 [0.5, 1.7] | 30/48 (62%) | 0.9 [0.4, 1.6] | |||||||
| Father | 28/35 (80%) | 1.8 [0.7, 5.0] | 26/33 (79%) | 1.9 [0.7, 5.2] | |||||||
| Other | 370/538 (69%) | 1.0 (ref) | 247/373 (66%) | 1.0 (ref) | |||||||
| Sleeping Proximity of IP to HHC | Same Room | 172/233(74%) | 1.3 [0.9, 1.8] | 0.13 | 142/201 (71%) | 1.2 [0.9, 1.7] | 0.29 | ||||
| Different Room | 299/453(66%) | 1.0 (ref) | 265/411 (64%) | 1.0 (ref) | |||||||
| Evenings/ Week with IC, Past 6 Mos. | 6–7 | 364/519 (70%) | 1.7 [1.1, 2.7] | 0.14 | 313/459 (68%) | 1.5 [0.9, 2.5] | 0.19 | ||||
| 3–5 | 48/71 (68%) | 1.5 [0.8, 2.9] | 38/61 (62%) | 1.2 [0.6, 2.4] | |||||||
| ≤2 | 58/95 (61%) | 1.0 (ref) | 56/92 (61%) | 1.0 (ref) | |||||||
| Sleeping Proximity, Evenings per Week with IC | Same Room/ Any Number | 172/233 (74%) | 1.9 [1.2, 3.2] | 0.10 | 2.4 [1.4, 4.2] | 0.046 | 142/201 (71%) | 1.7 [1.0, 2.9] | 0.19 | 2.2 [1.3, 3.9] | 0.070 |
| Different Room/ 6–7 | 218/320 (68%) | 1.7 [1.0, 2.8] | 2.1 [1.2, 3.5] | 192/287 (67%) | 1.6 [1.0, 2.7] | 2.1 [1.2, 3.6] | |||||
| Different Room/ 3–5 | 30/47 (64%) | 1.5 [0.7, 3.2] | 1.7 [0.7, 4.3] | 24/41 (59%) | 1.1 [0.5, 2.6] | 1.6 [0.6, 4.0] | |||||
| Different Room/≤2 | 51/86 (59%) | 1.0 (ref) | 1.0 (ref) | 49/83 (59%) | 1.0 (ref) | 1.0 (ref) | |||||
| Smokers in Householdb | Any | 205/267 (77%) | 1.8 [1.2, 2.6] | 0.005 | 1.6 [1.2, 2.5] | 0.023 | 164/222 (74%) | 1.6 [1.1, 2.5] | 0.020 | 1.6 [1.0, 2.5] | 0.029 |
| None | 264/410 (64%) | 1.0 (ref) | 1.0 (ref) | 241/381 (63%) | 1.0 (ref) | 1.0 (ref) | |||||
| Home Primary Exterior Wall Material | Brick, Cinderblock, Stone with Mortar | 356/534 (67%) | 1.0 (ref) | 0.022 | 1.0 (ref) | 0.007 | 306/476 (64%) | 1.0 (ref) | 0.020 | 1.0 (ref) | 0.004 |
| Adobe, Rammed Earth, Sticks/ Stones & Mud, Wood, Straw, Tin, Other | 114/148 (77%) | 1.6 [1.1, 2.5] | 1.9 [1.2, 2.9] | 100/132 (76%) | 1.7 [1.1, 2.6] | 2.0 [1.3, 3.2] | |||||
Abbreviations: IP, index participant; HHC, household contact; n, number of HHCs with positive IGRA result; N, number of HHCs with determinate IGRA result (positive or negative); %, simple percentage calculated as n/N; CI, confidence interval; ref, reference.
* Models use data from HHC ≥15 years of age with determinate IGRA results; eight HHCs with current active TB documented before study entry did not have specimen collection for IGRA, data collection on incarceration, TB symptoms, or HIV status; they also did not have chest x-ray, TB diagnostics, or HIV testing. Models were fit using an exchangeable working correlation, unless working correlation was negative (which occurred when data were sparse) in which case an independent working correlation was used. Univariable models include the one characteristic only. Each multivariable model includes characteristics with the odds ratios shown. The p values are from score tests.
a All self-reported using a recall period of 12 months. Incarceration is defined as having spent a night in jail, prison, youth detention center; alcohol use as having a period of drinking alcoholic beverages almost every day; and substance use as any use of substances (marijuana, cocaine, etc.).
b Smoking was defined as smoking of tobacco products, ongoing or having quit within the past 6 months.