Table 2. An optimal threshold to forecast culture negativity at the same visit and treatment failure using Xpert Ct at the end of the treatment.
| Concurrent culture negativity | Adjudicated treatment failure by week 24 | ||||||
|---|---|---|---|---|---|---|---|
| Culture Negative(Sensitivity) | Culture Positive(Specificity) | Selectedcutpoint | TreatmentFailure(Sensitivity) | TreatmentSuccess(Specificity) | Selectedcutpoint | ||
| XpertCt at given time | Baseline | NA | NA | NA | 62.5% (5/8) | 75.3% (61/81) | 17.6 |
| Week 4 | 94.1% (16/17) | 79.7% (59/74) | 29.8 | 71.4% (5/7) | 40.0% (32/80) | 29.7 | |
| Week 8 | 88.6% (47/53) | 76.3% (29/38) | 28.6 | 87.5% (7/8) | 59.0% (47/79) | 30.6 | |
| Week 24 | 87.9% (73/83) | 75% (6/8) | 29.7 | 75.0% (6/8) | 88.9% (72/81) | 29.7 | |
| Xpert baseline Ct & Delta Ct | Week 4 | 94.1% (16/17) | 79.7% (59/74) | NA | 57.1% (4/7) | 56.3% (54/80) | NA |
| Week 8 | 88.6% (47/53) | 73.6% (28/38) | NA | 75.0% (6/8) | 67.1% (53/79) | NA | |
| Week 24 | 89.2% (74/83) | 75.0% (6/8) | NA | 75.0% (6/8) | 88.9% (72/81) | NA | |
| Xpert baseline Ct and percent closing | Week 4 | 94.1% (16/17) | 81.1% (60/74) | NA | 71.4% (5/7) | 46.3% (37/80) | NA |
| Week 8 | 83.0% (44/53) | 71% (26/38) | NA | 62.5% (5/8) | 84.8% (67/79) | NA | |
| Week 24 | 89.2% (74/83) | 75.0% (6/8) | NA | 75.0% (6/8) | 88.9% (72/81) | NA | |