Table 2.
Sensitivity, Specificity, Positive predictive Value, Negative Predictive Value at different CAD4TB score thresholds among PWD, tested using Xpert MTB/RIF, visiting TB diagnostic and treatment centers in Karachi, Pakistan (Q3 2016-Q2 2017).
| CAD Score | Sensitivity (%) |
Specificity (%) |
PPV (%) |
NPV (%) |
No of Xpert tests saved | No of Total Xpert tests | No of TB Cases Missed | MTB+ |
|---|---|---|---|---|---|---|---|---|
| No triage test | — | — | — | — | — | 694 | 74 | |
| Cut-off 50 | 90.5% | 42.4% | 15.8% | 97.4% | 270 | 424 | 7 | 67 |
| Cut-off 60 | 83.7% | 58.6% | 19.4% | 96.8% | 375 | 319 | 12 | 62 |
| Cut-off 70 | 73.0% | 69.5% | 22.2% | 95.6% | 451 | 243 | 20 | 54 |
| Cut-off 80 | 63.5% | 78.7% | 26.3% | 94.8% | 515 | 179 | 27 | 47 |
| Cut-off 90 | 48.7% | 85.8% | 29.0% | 93.3% | 570 | 124 | 38 | 36 |