Table 3 Performance of drug-susceptibility testing with risk stratification for detection of drug-resistant tuberculosis (DR-TB)
From: Rationing tests for drug-resistant tuberculosis – who are we prepared to miss?
N | Percentage of subjects tested if only this subgroup was selected for drug-susceptibility testing (95 % CI) | DR-TB cases identified from subgroup (n) | Percentage of DR-TB cases identified (95 % CI) | DR-TB cases missed (n) | Percentage of DR-TB cases missed (95 % CI) | Numbers needed to test to identify one DR-TB case | |
|---|---|---|---|---|---|---|---|
All patients | 1,545 | 100.0 | 32 | 100.0 | 0 | 0.0 | 48 |
Patient subgroups | |||||||
≥1 MDR-TB risk factora | 553 | 35.8 (33.4–38.2) | 15 | 46.9 (29.6–64.2) | 17 | 53.1 (35.8–70.4) | 37 |
≥1 MDR-TB risk factor or smear positive sputumb | 604 | 39.1 (36.7–41.5) | 21 | 65.6 (49.2–82.1) | 11 | 34.4 (17.9–50.8) | 29 |
Sputum smear positive | 82 | 5.3 (4.2–6.4) | 14 | 43.8 (26.6–60.9) | 18 | 56.3 (39.1–73.4) | 6 |
Previous TB | 309 | 20.0 (18.0–22.0) | 11 | 34.4 (17.9–50.8) | 21 | 65.6 (49.2–97.0) | 28 |
Known contact with MDR-TB | 161 | 10.4 (8.9–11.9) | 5 | 15.6 (3.0–28.2) | 27 | 84.4 (71.8–97.0) | 32 |
Health worker | 66 | 4.3 (3.3–5.3) | 1 | 3.1 (0–9.2) | 31 | 96.9 (90.8–100.0) | 66 |
Current/ex prison worker or resident | 38 | 2.5 (1.7–3.2) | 1 | 3.1 (0–9.2) | 31 | 96.9 (90.8–100.0) | 38 |
HIV infection | 18 | 1.2 (0.6–107) | 0 | 0 | 32 | 100.0 | n/a |