Table 1 Performance of the Xpert MTB/RIF assay as stratified by smear status
From: Performance evaluation of the Xpert MTB/RIF assay according to its clinical application
Performance of the Xpert MTB/RIF assay | Total ( n =303) | Total ( n =271) a | Smear result (total, n =271) a | |
|---|---|---|---|---|
No./Total no.% (95% CI) | Â | Â | Smear-positive ( n =100) | Smear-negative ( n =171) |
Sensitivity | 95/104 | 95/104 | 76/79 | 19/25 |
91.3 (83.8-95.7) | 91.3 (83.8-95.7) | 96.2 (88.5-99.0) | 76.0 (54.5-89.8) | |
Specificity | 175/199 | 157/167 | 18/21 | 139/146 |
87.9 (82.4-92.0) | 94.0 (89.0-96.9) | 85.7 (62.6-96.2) | 95.2 (90.0-97.9) | |
PPV | 95/119 | 95/105 | 76/79 | 19/26 |
79.8 (71.3-86.4) | 90.5 (82.8-95.1) | 96.2 (88.5-99.0) | 73.1 (51.9-87.6) | |
NPV | 175/184 | 157/166 | 18/21 | 139/145 |
95.1 (90.6-97.6) | 94.6 (89.6-97.3) | 85.7 (62.6-96.2) | 95.9 (90.8-98.3) | |