Table 4.
Sensitivity, specificity, PPVs, NPVs, and overall agreement for measured PCR category, and ACR category imputed from PCR using model C4, at KDIGO category thresholds (reference standard: KDIGO category of measured ACR)
| KDIGO Category Threshold | Comparison with Category of Measured ACR | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | % Overall Agreement (95% CI) | ROC C-Statistic (95% CI) |
|---|---|---|---|---|---|---|---|
| A1/A2 | KDIGO category of measured PCR | 79.1 (78.5 to 79.7) | 93.3 (93.1 to 93.6) | 88.0 (87.4 to 88.4) | 87.9 (87.5 to 88.3) | 87.9 (87.6 to 88.2) | 0.86 (0.86 to 0.87) |
| ACR category imputed from PCR using model with cubic spline and all covariates (C4) | 83.2 (82.6 to 83.7) | 92.3 (92.0 to 92.6) | 86.9 (86.4 to 87.4) | 89.9 (89.6 to 90.3) | 88.8 (88.5 to 89.1) | 0.95 (0.95 to 0.96) | |
| A2/A3 | KDIGO category of measured PCR | 94.7 (94.1 to 95.2) | 98.0 (97.9 to 98.2) | 89.0 (88.3 to 89.7) | 99.1 (99.0 to 99.2) | 97.6 (97.4 to 97.7) | 0.96 (0.96 to 0.97) |
| ACR category imputed from model with cubic spline and all covariates (C4) | 95.4 (94.8 to 95.8) | 98.2 (98.0 to 98.3) | 89.7 (89.0 to 90.4) | 99.2 (99.1 to 99.3) | 97.8 (97.6 to 97.9) | >0.99 (>0.99 to >0.99) |
Values except ROC statistic are reported in percent. A1/A2 threshold: ACR=30 mg/g, PCR=150 mg/g. A2/A3 threshold: ACR=300 mg/g, PCR=500 mg/g. Positive cases are above the threshold. ROC, receiver operator characteristic.