Table 3. Diagnostic performance of nucleic acid amplification tests for TB stratified by HIV status, compared to the primary reference standard only.
| Index Test Results | Reference Positive(N) | Reference Negative(N) | Percent Sensitivity(95% CI) | Percent Specificity(95% CI) |
| Mycobacterial culture reference standard | 75 | 136 | ||
| HIV-seropositive patients | 67 | 103 | ||
| MTD | 42% (30–55) | 93% (87–97) | ||
| Positive | 28 | 7 | ||
| Negative | 39 | 96 | ||
| Indeterminate | - | - | ||
| secA1 | 25% (16–38) | 93% (86–97) | ||
| Positive | 17 | 7 | ||
| Negative | 50 | 95 | ||
| Indeterminate | - | 1 | ||
| HIV-seronegative patients | 8 | 33 | ||
| MTD | 13% (0–53) | 100% (89–100) | ||
| Positive | 1 | 0 | ||
| Negative | 7 | 33 | ||
| Indeterminate | - | - | ||
| secA1 | 13% (0–53) | 100% (89–100) | ||
| Positive | 1 | 0 | ||
| Negative | 7 | 33 | ||
| Indeterminate | - | - |
Abbreviations: CI, confidence interval; IQR, inter-quartile range; MTD, Gen-Probe Amplified® Mycobacterium Tuberculosis Direct test; secA1, secretory gene A1 target test; TB, tuberculosis.