Table 3.
Diagnostic performance of Xpert Ultra and AFB staining
| Specific specimen | Total number | Xpert Ultra | AFB smear | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sensitivity | Specificity | PPV | NPV | NND | CUI + | Sensitivity | Specificity | PPV | NPV | NND | CUI + | ||
| Tissue | 377 | 79% | 91% | 60% | 96% | 1.44 | 0.47 | 18% | 100% | 91% | 87% | 5.80 | 0.16 |
| Pleural fluid | 179 | 83% | 86% | 54% | 96% | 1.44 | 0.45 | 17% | 99% | 83% | 86% | 6.25 | 0.14 |
| Ascitic fluid | 32 | 75% | 93% | 60% | 96% | 1.47 | 0.45 | 25% | 100% | 100% | 90% | 4.00 | 0.25 |
| Biopsy | 41 | 50% | 94% | 60% | 92% | 2.26 | 0.30 | 0% | 100% | 0% | 85% | - | 0.00 |
| CSF | 38 | 78% | 97% | 88% | 93% | 1.35 | 0.68 | 0% | 97% | 0% | 76% | - | 0.00 |
| Gastric aspiration | 17 | 100% | 82% | 75% | 100% | 1.22 | 0.75 | 33% | 100% | 100% | 73% | 3.00 | 0.33 |
| Pus | 83 | 96% | 84% | 75% | 98% | 1.25 | 0.72 | 50% | 100% | 100% | 80% | 2.00 | 0.50 |
| Pericardial fluid | 18 | 67% | 93% | 67% | 93% | 1.67 | 0.44 | 0% | 100% | 0% | 83% | - | 0.00 |
| Peritoneal fluid | 20 | 50% | 94% | 50% | 94% | 2.25 | 0.25 | 0% | 100% | 0% | 90% | - | 0.00 |
| Synovial fluid | 13 | 100% | 78% | 67% | 100% | 1.29 | 0.67 | 25% | 100% | 100% | 75% | 4.00 | 0.25 |
| Other aspiration fluids | 9 | 75% | 100% | 100% | 83% | 1.33 | 0.75 | 0% | 100% | 0% | 56% | - | 0.00 |
| Others (stool, urine, swabs, abscess, FNA, bone) | 18 | 80% | 50% | 67% | 67% | 3.33 | 0.53 | 20% | 100% | 100% | 50% | 5.00 | 0.20 |
| All Specimens (Overall) | 845 | 82% | 89% | 64% | 95% | 1.40 | 0.53 | 21% | 100% | 92% | 84% | 4.75 | 0.20 |
CSF cerebrospinal fluid, FNA fine-needle aspirates, NND number needed to diagnose, CUI+ clinical utility index (< 0.2, poor; > 0.2 to < 0.4, fair; > 0.4 to < 0.6, moderate; > 0.6 to < 0.8, good; and > 0.8 to < 1, excellent); PPV positive predictive value, NPV negative predictive value