Table 1.
Baseline characteristics of study cohort
| All (n=181) | No tuberculosis (n=127) | Positive for pulmonary tuberculosis (n=54) | ||
|---|---|---|---|---|
| Age, years | 35 (27–48) | 36 (28–49) | 34 (24–43) | |
| Sex | ||||
| Male | 94 (52%) | 66 (52%) | 28 (52%) | |
| Female | 87 (48%) | 61 (48%) | 26 (48%) | |
| Ethnicity | ||||
| Black | 28 (15%) | 14 (11%) | 14 (26%) | |
| Mixed ancestry | 153 (85%) | 113 (89%) | 40 (74%) | |
| HIV status | ||||
| Unknown* | 1 (1%) | 1 (1%) | 0 | |
| Uninfected | 136 (75%) | 99 (78%) | 37 (69%) | |
| Infected | 44 (24%) | 27 (21%) | 17 (31%) | |
| Antiretroviral therapy† | ||||
| No | 24 (55%) | 14 (52%) | 10 (59%) | |
| Yes | 15 (34%) | 12 (44%) | 3 (18%) | |
| Unknown* | 5 (11%) | 1 (4%) | 4 (24%) | |
| CD4 count†, cells per μL | 334 (192–606) | 354 (207–707) | 326 (128–484) | |
| Haemoglobin concentration, g/dL | 13·7 (12·4–14·8) | 14·2 (13·2–15·4) | 12·6 (11·3–13·6) | |
| Leucocyte count, × 109 cells per L | 8 (6·1–10·2) | 7·6 (6–9·8) | 9·1 (6·8–11) | |
| BMI, kg/m2 | 19·9 (17·8–22·5) | 20·5 (18·4–23·2) | 19·1 (16·8–21·5) | |
| Tuberculosis symptom score | 2 (2–3) | 2 (1–3) | 3 (2–5) | |
| Previous tuberculosis | ||||
| No | 115 (64%) | 81 (64%) | 34 (63%) | |
| Yes | 66 (36%) | 46 (36%) | 20 (37%) | |
| Liquid culture | ||||
| Positive | 53 (29%) | NA | 53 (98%) | |
| Negative | 128 (71%) | 128 (100%) | 1 (2%) | |
| Sputum smear | ||||
| Positive | 15 (8%) | 1 (1%) | 14 (26%) | |
| Negative | 157 (87%) | 120 (94%) | 37 (69%) | |
| Not done | 9 (5%) | 6 (5%) | 3 (6%) | |
| Xpert | ||||
| Positive | 44 (24%) | NA | 44 (81%) | |
| Negative | 134 (74%) | 124 (98%) | 10 (19%) | |
| No result | 2 (2%) | 2 (2%) | NA | |
| Not done | 1 (1%) | 1 (1%) | NA | |
| Ultra | ||||
| Positive‡ | 51 (28%) | 10 (8%) | 41 (76%) | |
| Negative | 103 (57%) | 94 (74%) | 9 (17%) | |
| No result | 10 (6%) | 8 (6%) | 2 (4%) | |
| Not done | 17 (9%) | 15 (12%) | 2 (4%) | |
Data are n (%) or median (IQR). Individuals positive for pulmonary tuberculosis were defined as those with either a positive liquid culture or a positive Xpert MTB/RIF result, or both. Individuals with missing data: CD4 cell counts (n=1), haemoglobin concentration (n=3), leucocytes (n=3), BMI (n=1), symptom score (n=3). BMI=body-mass index. NA=not applicable.
*
Category excluded for χ2 statistical test.
†
Antiretroviral therapy and CD4 cell counts for HIV-infected patients only.
‡
Positive Ultra results include tests where traces of Mycobacterium tuberculosis were detected.