Table 3 Accuracy of one or two oral swab PCR tests when using two different positive reference standards and Unlikely TB as the negative reference standard.
Sensitivity reference standard | Index method | Sensitivity n (%) (95% CI) | Specificity n (%)a (95% CI) | Positive LRb (95% CI) | Negative LR (95% CI) |
|---|---|---|---|---|---|
Confirmed TB | OS1c | 12/40 (30) (17–47) | 44/44 (100) (92–100) | NAd | 0.7 (0.6–0.9) |
Confirmed TB | OS1 OR OS2 | 17/40 (43) (27–59) | 41/44 (93) (81–99) | 6.2 (2–20) | 0.6 (0.5–0.8) |
Confirmed TB | ISe Xpert MTB/RIF | 23/36 (64) (46–79) | 43/43 (100) (92–100) | NA | 0.4 (0.2–0.6) |
Confirmed + Unconfirmed TB | OS1 | 21/111 (19) (12–27) | 43/43 (100) (92–100) | NA | 0.8 (0.7–0.9) |
Confirmed + Unconfirmed TB | OS1 OR OS2 | 34/111 (31) (22–40) | 40/43 (93) (81–99) | 4.4 (1–14) | 0.8 (0.6–0.9) |
Confirmed + Unconfirmed TB | IS Xpert MTB/RIF | 23/111 (21) (14–29) | 43/43 (100) (92–100) | NA | 0.8 (0.7–0.9) |
