Table 5. Β2-microglobulin level cut-off levels that may be used to identify patients with residual renal urea clearance.
For various levels of residual urea clearance, the cut-off β2-microglobulin level was determined that would yield a false positive rate (specificity) of 10%. For each level of urea clearance area under the curve (AUC) is shown for ROC analyses.
| RKF level (ml/min/1.73m2 urea clearance) | Number of patients with RKF ≥ level in column 1 in cohort | Cut-off β2m microglobulin level (mg/L) for positive test | Sensitivity | Specificity | AUC |
|---|---|---|---|---|---|
| 1 | 139 | ≤23.30 | 0.72 | 0.90 | 0.92 |
| 2 | 79 | ≤19.15 | 0.65 | 0.90 | 0.91 |
| 3 | 46 | ≤18.40 | 0.73 | 0.90 | 0.94 |
| 4 | 19 | ≤16.70 | 0.63 | 0.90 | 0.91 |
| 5 | 7 | ≤16.30 | 1.00 | 0.90 | 0.96 |
AUC: Area under the curve