Table 5.
Diagnostic performance of pleural fluid PCT based on the ROC analysis (n = 132)
| Optimal cut-off point (ng/mL) | Sensitivity (%) | Specificity (%) | +LR | −LR | PPV (%) | NPV (%) | AUC | Accuracy (%) | |
|---|---|---|---|---|---|---|---|---|---|
| Emp vs. other | ≤2.57 | 100.0 | 5.8 | 1.06 | 0.00 | 8.8 | 100.0 | 0.244 | 13.6 |
| Emp and PE vs. other | ≥0.19 | 70.4 | 83.8 | 4.35 | 0.35 | 52.8 | 91.7 | 0.791 | 81.1 |
| Emp, PE and TB vs. other | ≥0.11 | 66.7 | 75.0 | 2.67 | 0.44 | 50.0 | 85.7 | 0.718 | 72.7 |
| PE vs. other (excluding Emp) | ≥0.13 | 75.0 | 79.0 | 3.58 | 0.32 | 35.3 | 95.4 | 0.783 | 78.5 |
| Infectious vs. non-infectious | ≥0.11 | 63.2 | 74.5 | 2.47 | 0.49 | 50.0 | 83.3 | 0.696 | 71.2 |
Emp empyema, PE parapneumonic effusion, TB tuberculosis, +LR positive likelihood ratio, −LR negative likelihood ratio, PPV positive predictive value, NPV negative predictive value, AUC area under the curve