Table 2.
Bovine respiratory disease positive predictive and negative predicted values, sensitivity and specificity as determined from Response Operant Characteristic (ROC) analysis.
| Parameter | COVa | PPVb | NPVc | Sensitivity | Specificity | P |
|---|---|---|---|---|---|---|
| Clinical scores | >3 | 61.2 | 100 | 100 | 89.7 | P < 0.01 |
| Core temp (°C) | 39.55 | 86.3 | 100 | 100 | 97.4 | P < 0.01 |
| White blood cells (×103/μL−1) | 10.2 | 41.2 | 95.8 | 77.8 | 82.1 | P < 0.01 |
| Neutrophil/lymphocyte ratio | 0.074 | 34.4 | 93.7 | 66.7 | 79.5 | P = 0.02 |
| Serum cortisol (μmol/L) | 105.9 | 25.9 | 100 | 100 | 53.8 | P < 0.01 |
| IRT absolute valued | 35.29 | 86.3 | 100 | 100 | 97.4 | P |
| IRT mean ratioe | 1.005 | 55.7 | 100 | 100 | 87.2 | P < 0.01 |
a
Optimal cut off value as determined by ROC analysis.
b
Positive predictive value.
c
Negative predictive value.
d
Infrared thermal value of the TP animals at peak temperature and TN animals at their average maximum infrared thermal value.
e
Ratio of the peak infrared values for the TP/ave infrared values for the TN animals.