Table 5.
(a) Sensitivity, specificity, and negative and positive predictive values of predicted ionized calcium and its prediction interval, total calcium, and 2 corrected calcium formulas for diagnosis of hypocalcemia in dogs of the test set (prevalence of hypocalcemia = 15%). (b) Sensitivity, specificity, and negative and positive predictive values of predicted calcium and its prediction interval, total calcium, and 2 corrected calcium formulas for diagnosis of hypercalcemia in dogs of the test set (prevalence of hypercalcemia = 5.4%)
| Sensitivity | Specificity | NPV | PPV | PDLR | NDLR | |
|---|---|---|---|---|---|---|
| (a) | ||||||
| piCa < 1.11 mmol/L | 21.8% | 98.4% | 87.7% | 70.8% | 13.7 | 0.79 |
| Lower end of PI < 1.11 mmol/L | 97.4% | 21.3% | 97.9% | 18% | 1.2 | 0.12 |
| Upper end of PI < 1.11 mmol/L | 2.6% | 100% | 85.3% | 100% | ND | 0.97 |
| tCa < 7.6 mg/dL | 6.4% | 98.6% | 85.6% | 45.5% | 4.7 | 0.95 |
| Corrected tCa1 < 7.6 mg/dL | 0% | 100% | ND | 15% | ND | 1 |
| Corrected tCa2 < 7.6 mg/dL | 0% | 100% | ND | 15% | ND | 1 |
| (b) | ||||||
| piCa > 1.37 mmol/L | 64% | 99.6% | 98% | 90% | 157.8 | 0.36 |
| Upper end of PI > 1.37 mmol/L | 92.9% | 79.2% | 99.5% | 20.3% | 4.5 | 0.09 |
| Lower end of PI > 1.37 mmol/L | 35.7% | 100% | 96.5% | 100% | ND | 0.64 |
| tCa > 11.4 mg/dL | 71.4% | 98% | 98.4% | 66.7% | 35.1 | 0.29 |
| Corrected tCa1 > 11.4 mg/dL | 82.1% | 95.9% | 98.9% | 53.5% | 20.1 | 0.19 |
| Corrected tCa2 > 11.4 mg/dL | 78.6% | 89.6% | 98.7% | 30.1% | 7.5 | 0.24 |
piCa, predicted ionized calcium; PI, prediction interval; tCa, total calcium; Corrected tCa1, total calcium corrected with albumin; Corrected tCa2, total calcium corrected with total protein; NPV, negative predictive value; PPV, positive predictive value; PDLR, positive diagnostic likelihood ratio; NDLR, negative diagnostic likelihood ratio; ND, not determined because denominator is 0.