Table 1.
Comparative ROC analysis of milk samples with 90 min and overnight incubation time using Youden and maximum specificity as criteria
| Criterion | Youden | Maximum specificity | ||
|---|---|---|---|---|
| Incubation | 90 min | overnight | 90 min | overnight |
| Area under ROC curve (ACU) | 0.961 (0.942, 0.98) | 0.932 (0.887, 0.977) | 0.959 (0.939, 0.978) | 0.92 (0.87, 0.971) |
| cut-off | 1.308 | 3.086 | 9.425 | 9.785 |
| Se | 0.895 | 0.882 | 0.513 | 0.632 |
| Sp | 0.891 | 0.914 | 1.0 | 1.0 |
| PPV | 0.591 | 0.644 | 1.0 | 1.0 |
| NPV | 0.980 | 0.978 | 0.921 | 0.939 |
| DLR. Positive | 8.186 | 10.222 | Inf | Inf |
| DLR. Negative | 0.118 | 0.13 | 0.487 | 0.368 |
| FP | 47.0 | 37.0 | 0.0 | 0.0 |
| FN | 8.0 | 9.0 | 37.0 | 28.0 |
| Optimal criterion | 0.785 | 0.795 | ||