Table 4.
Diagnostic performance of pleural fluid CRP based on the ROC analysis (n = 132)
| Optimal cut-off point (mg/dL) | Sensitivity (%) | Specificity (%) | +LR | −LR | PPV (%) | NPV (%) | AUC | Accuracy (%) | |
|---|---|---|---|---|---|---|---|---|---|
| Emp vs. other | ≥4.91 | 63.6 | 89.3 | 5.93 | 0.41 | 35.0 | 96.4 | 0.757 | 87.1 |
| Emp and PE vs. other | ≥2.59 | 70.4 | 85.7 | 4.92 | 0.35 | 55.9 | 91.8 | 0.834 | 82.6 |
| Emp, PE and TB vs. other | ≥2.59 | 69.4 | 90.6 | 7.40 | 0.34 | 73.5 | 88.8 | 0.840 | 84.9 |
| PE vs. other (excluding Emp) | ≥2.18 | 81.3 | 81.0 | 4.27 | 0.23 | 39.4 | 96.6 | 0.859 | 81.0 |
| Infectious vs. non-infectious | ≥2.59 | 65.8 | 90.4 | 6.87 | 0.38 | 73.5 | 86.7 | 0.820 | 83.3 |
Emp empyema, PE parapneumonic effusions, TB tuberculosis, +LR positive likelihood ratio −LR negative likelihood ratio, PPV positive predictive value, NPV negative predictive value, AUC area under the curve