Table 7.
Sensitivity, specificity, and the positive and negative predictive values of various selected laboratory tests performed on admission to predict the later requirement for dialysis^: optimal cut-offs in this series
| Index | Optimal cut off** | Sensitivity | Specificity | PPV | NPV |
|---|---|---|---|---|---|
| Plasma creatinine μmol/L | 202 | 77 | 78 | 75 | 80 |
| RFI | 1.4 | 71 | 72 | 69 | 74 |
| FeNa | 1.88 | 50 | 91 | 83 | 67 |
| Urine Osmolality mosm/L | 419 | 63 | 56 | 56 | 63 |
| UPCR | 43 | 84 | 44 | 57 | 76 |
| Urinary Sodium mmol/L | 34 | 90 | 44 | 59 | 83 |
| Bicarbonate | 15 | 82 | 56 | 62 | 78 |
| NGAL | 510 | 65 | 70 | 65 | 70 |
AUC: Area under receiver operating characteristic curve, RFI: Renal failure index, FeNa: Fractional excretion of sodium, UPCR: Urine: plasma creatinine ratio, FUN: Fractional excretion urea. NGAL: neutrophil gelatinase-associated lipocalcin.
** Determined using the ROC curve
^ Patients who should have had dialysis.