Factors associated with TB clustering; a univariable logistic regression analysis, universal MIRU-VNTR, London 2010–2012
| Variable | Total no of cases | No (%) clustered | OR (95% CI) | p Value* |
|---|---|---|---|---|
| Gender | 4788 | |||
| Female | 1876 | 830 (44.2) | Reference | |
| Male | 2912 | 1363 (46.8) | 1.1 (1.0 to 1.2) | 0.08 |
| Age | 4790 | |||
| 0–4 | 18 | 16 (88.9) | 9.3 (2.1 to 40.4) | <0.01 |
| 5–9 | 15 | 10 (66.7) | 2.3 (0.8 to 6.8) | 0.13 |
| 10–14 | 76 | 44 (57.9) | 1.6 (1.0 to 2.5) | 0.05 |
| 15–19 | 266 | 162 (60.9) | 1.8 (1.4 to 2.3) | <0.01 |
| 20–29 | 1628 | 755 (46.4) | Reference | |
| 30–39 | 1169 | 509 (43.5) | 0.9 (0.8 to 1.0) | 0.14 |
| 40–49 | 679 | 298 (43.9) | 0.9 (0.7 to 1.1) | 0.27 |
| 50–59 | 421 | 187 (44.4) | 0.9 (0.7 to 1.1) | 0.47 |
| 60–69 | 252 | 114 (45.2) | 1.0 (0.7 to 1.2) | 0.74 |
| >70 | 266 | 99 (37.2) | 0.7 (0.5 to 0.9) | 0.01 |
| UK/non-UK born and ethnicity | ||||
| UK born | ||||
| Indian | 68 | 39 (57.4) | 2.2 (1.4 to 3.6) | <0.01 |
| Pakistani | 32 | 18 (56.3) | 2.1 (1.0 to 4.3) | 0.04 |
| Bangladeshi | 26 | 12 (46.2) | 1.4 (0.6 to 3.1) | 0.38 |
| White | 305 | 186 (61.0) | 2.6 (2.0 to 3.3) | <0.01 |
| Black-Caribbean | 95 | 79 (83.2) | 8.1 (4.7 to 14.1) | <0.01 |
| Black-African | 110 | 86 (78.2) | 5.9 (3.7 to 9.4) | <0.01 |
| Other† | 74 | 54 (72.3) | 4.5 (2.6 to 7.5) | <0.01 |
| Non-UK born | ||||
| Indian | 1364 | 515 (37.8) | Reference | |
| Pakistani | 395 | 163 (41.3) | 1.2 (0.9 to 1.5) | 0.21 |
| Bangladeshi | 205 | 51 (24.9) | 0.5 (0.4 to 0.8) | <0.01 |
| White | 186 | 79 (42.5) | 1.2 (0.9 to 1.7) | 0.22 |
| Black-Caribbean | 74 | 49 (66.2) | 3.2 (2.0 to 5.3) | <0.01 |
| Black-African | 969 | 518 (53.5) | 1.9 (1.6 to 2.2) | <0.01 |
| Other† | 777 | 297 (38.2) | 1.0 (0.9 to 1.2) | 0.83 |
| Born in UK | 4711 | |||
| UK | 714 | 476 (66.7) | 2.8 (2.3 to 3.3) | <0.01‡ |
| Non-UK born | 3997 | 1678 (42.0) | Reference | |
| If non-UK born, time since arrival | 3406 | |||
| In UK <2 years | 811 | 340 (41.9) | Reference | |
| In UK 2–4 years | 835 | 310 (37.1) | 0.8 (0.7 to 1.0) | 0.05 |
| In UK 5–9 years | 703 | 309 (44.0) | 1.1 (0.9 to 1.3) | 0.43 |
| In UK >9 years | 1057 | 479 (45.3) | 1.1 (1.0 to 1.4) | 0.14 |
| Country of birth | 3290 | |||
| UK | 714 | 476 (66.7) | Reference | |
| India | 1224 | 457 (37.3) | 0.3 (0.2 to 0.4) | <0.01‡ |
| Pakistan | 384 | 159 (41.4) | 0.4 (0.3 to 0.5) | 0.14 |
| Somalia | 431 | 269 (62.4) | 0.8 (0.6 to 1.1) | <0.01‡ |
| Bangladesh | 208 | 50 (24.0) | 0.2 (0.1 to 0.2) | <0.01‡ |
| Nepal | 189 | 102 (54.0) | 0.6 (0.4 to 0.8) | <0.01‡ |
| Nigeria | 140 | 69 (49.3) | 0.5 (0.3 to 0.7) | <0.01‡ |
| London health protection team | 4790 | |||
| North-East and central | 1932 | 887 (45.9) | Reference | |
| North-West | 1647 | 741 (45.0) | 1.0 (0.8 to 1.1) | 0.58 |
| South-East | 696 | 343 (49.3) | 1.1 (1.0 to 1.4) | 0.13 |
| South-West | 515 | 223 (43.3) | 0.9(0.7 to 1.1) | 0.29 |
| Social risk factors | 4670 | |||
| Any | 493 | 279 (56.6) | 1.6 (1.3 to 1.9) | <0.01‡ |
| None | 4177 | 1866 (44.7) | Reference | |
| Imprisonment | 4557 | |||
| Yes | 154 | 105 (68.2) | 2.6 (1.9 to 3.7) | <0.01‡ |
| No | 4403 | 1983 (45.0) | Reference | |
| Homelessness | 4624 | |||
| Yes | 202 | 109 (54.0) | 1.4 (1.1 to 1.9) | 0.02 |
| No | 4422 | 2008 (45.4) | Reference | |
| Alcohol misuse | 4273 | |||
| Yes | 203 | 117 (57.6) | 1.7 (1.2 to 2.2) | <0.01‡ |
| No | 4070 | 1837 (45.1) | Reference | |
| Drug misuse | 4521 | |||
| Yes | 174 | 119 (68.4) | 2.7 (1.9 to 3.7) | <0.01 |
| No | 4357 | 1947 (44.8) | Reference | |
| Alcohol misuse and prison history | 4214 | |||
| Yes | 35 | 30 (85.7) | 7.3 (2.8 to 18.7) | <0.01 |
| No | 4179 | 1891 (45.3) | Reference | |
| Clinical presentation | 4790 | |||
| Extrapulmonary | 760 | 760 (38.5) | Reference | |
| Pulmonary smear negative | 1107 | 546 (49.3) | 1.6 (1.3 to 1.8) | <0.01 |
| Pulmonary smear positive | 1247 | 667 (53.5) | 1.8 (1.6 to 2.1) | <0.01 |
| Pulmonary smear status unknown | 464 | 221 (47.6) | 1.5 (1.2 to 1.8) | <0.01 |
| Previous TB | 4567 | |||
| Yes | 198 | 119 (60.1) | 1.8 (1.4 to 2.5) | <0.01 |
| No | 4369 | 1968 (45.0) | Reference | |
| Resistance | 4784 | |||
| Any | 447 | 215 (48.1) | 1.1 (0.9 to 1.3) | 0.30 |
| None | 4337 | 1975 (45.5) | Reference | |
| Isoniazid mono-resistant | 4784 | |||
| Yes | 239 | 118 (49.4) | 1.2 (0.9 to 1.5) | 0.25 |
| No | 4545 | 2072 (45.6) | Reference | |
| MDR TB | 4784 | |||
| Yes | 81 | 43 (53.1) | 1.3 (0.9 to 2.1) | 0.19 |
| No | 4703 | 2147 (45.7) | Reference | |
| BCG vaccination | 3741 | |||
| Yes | 2727 | 1251 (45.9) | 1.0 (0.9 to 1.2) | 0.96 |
| No | 1014 | 466 (46.0) | Reference | |
| Year of notification | 4790 | |||
| 2010 | 1242 | 565 (45.5) | Reference | |
| 2011 | 1716 | 758 (44.2) | 0.9 (0.8 to 1.1) | 0.48 |
| 2012 | 1832 | 871 (47.5) | 1.1 (0.9 to 1.3) | 0.26 |
*Significant results are in bold, those p≤0.2 included in multivariable model.
†‘Other’ ethnicity category includes all those who stated their ethnicity was Chinese, black-other or mixed/other.
‡Not included in final model due to colinearity with an included variable.
MDR, multi drug resistant; MIRU-VNTR, multiple interspersed repetitive units-variable number tandem repeats.