Univariate and multivariate analysis of factors associated with tuberculin skin test, QuantiFERON Gold in-tube and T-SPOT.TB positivity
| Variable | No. TST positive/total no. tested, n=175 | Unadjusted OR (95% CI) | Adjusted OR* (95% CI) | p | No. QFN-G-IT positive/total no. tested, n=229 | Unadjusted OR (95% CI) | Adjusted OR* (95% CI) | p | No. T.SPOT.TB positive/total no. tested, n=160 | Unadjusted OR (95% CI) | Adjusted OR* (95% CI) | p |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age (years) | ||||||||||||
| 16–25 | 16/63 (25.4%) | 1 | 1 | 0.008 | 12/86 (14.0%) | 1 | 1 | 0.003‡ | 11/63 (17.5%) | 1 | 1 | 0.03 |
| 26–35 | 23/61 (37.7%) | 1.78 (0.82 to 3.83) | 2.82 (1.06 to 7.46) | 10/84 (11.9%) | 0.83 (0.34 to 2.05) | 1.49 (0.51 to 4.41) | 8/49 (16.3%) | 0.92 (0.34 to 2.50) | 1.40 (0.42 to 4.69) | |||
| 36–45 | 18/28 (64.3%) | 5.29 (2.03 to 13.79) | 7.49 (2.31 to 24.31) | 8/34 (23.5%) | 1.90 (0.70 to 5.16) | 2.49 (0.68 to 9.06) | 11/30 (36.7%) | 2.74 (1.02 to 7.34) | 5.76 (1.55 to 21.39) | |||
| >45 | 9/23 (39.1%) | 1.89 (0.69 to 5.19) | 4.51 (1.22 to 16.69) | 8/25 (32.0%) | 2.90 (1.03 to 8.20) | 6.23 (1.47 to 26.33) | 6/18 (33.3%) | 2.36 (0.73 to 7.66) | 3.54 (0.72 to 17.33) | |||
| Gender | ||||||||||||
| Women | 33/106 (31.1%) | 1 | 1 | 0.19 | 23/147 (15.7%) | 1 | 1 | 0.72 | 22/105 (21.0%) | 1 | 1 | 0.33 |
| Men | 33/69 (22.4%) | 2.03 (1.08 to 3.79) | 1.71 (0.77 to 3.79) | 15/82 (18.3%) | 1.21 (0.59 to 2.47) | 1.19 (0.46 to 3.06) | 14/55 (25.5%) | 1.29 (0.60 to 2.78) | 0.59 (0.20 to 1.72) | |||
| World region of origin† | ||||||||||||
| Europe, Americas | 3/56 (11.5%) | 1 | 0/30 (0.0%) | – | 1/16 (6.3%) | 1 | ||||||
| Middle East, North Africa | 7/19 (36.8%) | 4.47 (0.98 to 20.49) | 2/24 (8.3%) | 1 | 2/12 (16.7%) | 3.00 (0.24 to 37.67) | ||||||
| Other Asia | 36/78 (46.2%) | 6.57 (1.82 to 23.70) | 20/96 (20.8%) | 2.89 (0.63 to 13.36) | 20/71 (28.2%) | 5.88 (0.73 to 47.52) | ||||||
| Indian subcontinent | 11/32 (34.4%) | 4.02 (0.98 to 16.40) | 7/49 (14.3%) | 1.83 (0.35 to 9.58) | 5/42 (11.9%) | 2.03 (0.22 to 18.84 | ||||||
| Sub-Saharan Africa | 9/20 (45.0%) | 6.27 (1.41 to 27.86) | 9/30 (30.0%) | 4.71 (0.91 to 24.42) | 8/19 (42.1%) | 10.91 (1.19 to 100.41) | ||||||
| TB incidence in country of origin (per 100 000 p.a.)† | ||||||||||||
| ≤65 | 6/30 (20.0%) | 1 | 1 | 0.007 | 2/39 (5.1%) | 1 | 1 | 0.007 | 2/18 (11.1%) | 1 | 1.75 (0.31 to 9.84) | 0.037 |
| 66–170 | 31/84 (36.9%) | 2.34 (0.86 to 6.35) | 4.50 (1.44 to 14.07) | 12/103 (11.7%) | 2.44 (0.52 to 11.44) | 3.58 (0.69 to 18.62) | 12/73 (16.4%) | 1.57 (0.32 to 7.76) | 6.28 (1.07 to 36.92) | |||
| 171–300 | 27/56 (48.2%) | 3.72 (1.32 to 10.5) | 10.29 (2.79 to 37.97) | 22/74 (29.7%) | 7.83 (1.73 to 35.35) | 13.92 (2.48 to 78.07) | 19/63 (30.2%) | 3.45 (0.72 to 16.53) | ||||
| >300 | 2/5 (40.0%) | 2.67 (0.36 to 19.71) | 5.95 (0.61 to 58.18) | 2/13 (15.4%) | 3.36 (0.42 to 26.72) | 8.07 (0.82 to 79.49) | 3/6 (50.0%) | 8.00 (0.91 to 70.27) | 9.64 (0.77 to 121.31) | |||
| Time since arrival in the UK (years) | ||||||||||||
| <1 | 10/25 (40.0%) | 1 | 1 | 0.11 | 5/36 (13.9%) | 1 | 1 | 0.88 | 5/13 (38.5%) | 1 | 1 | 0.09 |
| 1–2 | 35/89 (39.3%) | 0.97 (0.39 to 2.41) | 0.89 (0.31 to 2.56) | 15/105 (14.3%) | 1.03 (0.35 to 3.08) | 0.80 (0.23 to 2.84) | 16/81 (19.8%) | 0.39 (0.11 to 1.37) | 0.22 (0.05 to 1.00) | |||
| 3–5 | 21/61 (34.4%) | 0.79 (0.30 to 2.05) | 0.37 (0.12 to 1.20) | 18/88 (20.5%) | 1.59 (0.54 to 4.68) | 0.98 (0.27 to 3.59) | 15/66 (22.7%) | 0.47 (0.13 to 1.65) | 0.17 (0.03 to 0.85) | |||
| BCG vaccinated | ||||||||||||
| No | 8/29 (27.6%) | 1 | 1 | 0.40 | 7/37 (18.9%) | 1 | 1 | 0.75 | 4/25 (16.0%) | 1 | 1 | 0.57 |
| Yes | 57/143 (39.9%) | 1.74 (0.72 to 4.20) | 1.56 (0.56 to 4.33) | 30/188 (16.0%) | 0.81 (0.33 to 2.02) | 0.84 (0.30 to 2.40) | 31/132 (23.5%) | 1.61 (0.51 to 5.05) | 1.46 (0.40 to 5.28) | |||
| Travel to TB endemic country | ||||||||||||
| No | 41/121 (33.9%) | 1 | 1 | 0.18 | 21/159 (13.2%) | 1 | 1 | 0.06 | 21/111 (18.9%) | 1 | 1 | 0.08 |
| Yes | 25/54 (46.3%) | 1.68 (0.87 to 3.24) | 1.77 (0.77 to 4.06) | 17/70 (24.3%) | 2.11 (1.03 to 4.30) | 2.25 (0.96 to 5.26) | 15/49 (30.6%) | 1.89 (0.87 to 4.09) | 2.37 (0.90 to 6.28) | |||
| TB contact | ||||||||||||
| No | 60/164 (36.6%) | 1 | 1 | 0.23 | 33/215 (15.4%) | 1 | 1 | 0.14 | 31/148 (21.0%) | 1 | 1 | 0.07 |
| Yes | 6/9 (66.7%) | 3.47 (0.84 to 14.36) | 2.71 (0.53 to 13.82) | 5/13 (38.5%) | 3.44 (1.06 to 11.19) | 2.93 (0.72 to 12.01) | 5/11 (45.5%) | 3.15 (0.9 to 10.99) | 4.01 (0.92 to 17.48) | |||
| Employment status | ||||||||||||
| Unemployed | 18/51 (35.3%) | 1 | 1 | 0.55 | 15/65 (23.1%) | 1 | 1 | 0.25 | 11/53 (20.8%) | 1 | 1 | 0.10 |
| Employed | 27/70 (38.6%) | 1.15 (0.54 to 2.44) | 0.92 (0.36 to 2.37) | 13/99 (13.1%) | 0.50 (0.22 to 1.14) | 0.46 (0.16 to 1.3) | 14/63 (22.2%) | 1.09 (0.45 to 2.66) | 0.96 (0.31 to 2.98) | |||
| Student | 21/54 (38.9%) | 1.20 (0.50 to 2.60) | 1.49 (0.58 to 3.83) | 10/65 (15.4%) | 0.61 (0.25 to 1.47) | 1.06 (0.36 to 3.1) | 11/44 (25.0%) | 1.27 (0.49 to 3.30) | 3.13 (0.94 to 10.4) | |||
| Alcohol | ||||||||||||
| No | 48/131 (36.6%) | 1 | 1 | 0.79 | 30/167 (18.0%) | 1 | 1 | 0.97 | 27/126 (21.4%) | 1 | 1 | 0.10 |
| Yes | 18/44 (40.9%) | 1.20 (0.60 to 2.41) | 1.13 (0.46 to 2.78) | 8/62 (12.9%) | 0.68 (0.29 to 1.57) | 1.02 (0.35 to 3.02) | 9/34 (26.5%) | 1.32 (0.55 to 3.16) | 2.78 (0.83 to 9.23) | |||
| Smoker | ||||||||||||
| No | 56/146 (38.4%) | 1 | 1 | 0.73 | 34/193 (17.6%) | 1 | 1 | 0.75 | 33/136 (24.3%) | 1 | 1 | 0.75 |
| Yes | 10/29 (34.5%) | 0.85 (0.37 to 1.95) | 1.21 (0.41 to 3.58) | 4/36 (11.1%) | 0.58 (0.19 to 1.76) | 1.25 (0.32 to 4.80) | 3/24 (12.5%) | 0.45 (0.13 to 1.59) | 0.77 (0.15 to 3.88) | |||
| History of imprisonment | ||||||||||||
| No | 65/172 (37.8%) | 1 | 1 | 0.83 | 38/226 (16.8%) | 35/157 (22.3%) | 1 | 1 | 0.16 | |||
| Yes | 1/3 (33.3%) | 0.82 (0.07 to 9.26) | 1.34 (0.09 to 19.49) | 0/3 (0.0%) | 1/3 (33.3%) | 1.74 (0.15 to 19.79) | 7.79 (0.46 to 132.76) | |||||
↵* Models mutually adjusted for the following factors: age, gender, TB incidence in country of origin, time since arrival in the UK, BCG vaccination status, travel to TB endemic country, history of TB contact, employment status, alcohol use, smoking status and history of imprisonment (except for QuantiFERON Gold in-tube).
↵† World region of origin and TB incidence in country of origin were strongly correlated, so, in the multivariate analysis, world region of origin was dropped.
BCG, bacille Calmette Guérin; QFN, QuantiFERON Gold in-tube; TB, tuberculosis; TST, tuberculin skin test.