Diagnostic accuracy of serum and pleural fluid procalcitonin for complicated parapneumonic effusion in sub-groups
| Sub-group | Sample type | Number of patients | AUC (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) |
| Pleural fluid pH ≤7.2 | Serum | n=20 | 0.81 (0.61 to 1.00) | 91% (59 to 100%) | 67% (30 to 93%) | 77% (46 to 95%) | 86% (42 to 100%) |
| Pleural fluid | n=20 | 0.60 (0.34 to 0.86) | 82% (48 to 97%) | 56% (21 to 86%) | 69% (39 to 91%) | 72% (29 to 96%) | |
| Excluding inpatient stay >48 h | Serum | n=98 | 0.83 (0.69 to 0.97) | 78% (49 to 95%) | 85% (75 to 92%) | 46% (25 to 67%) | 96% (88 to 99%) |
| Pleural fluid | n=89 | 0.86 (0.78 to 0.99) | 92% (64 to 100%) | 84% (74 to 92%) | 50% (29 to 71%) | 98% (92 to 100%) | |
| Excluding antibiotics for >48 h | Serum | n=81 | 0.98 (0.94 to 1.00) | 100% (48 to 100%) | 86% (67 to 93%) | 31% (11 to 59%) | 100% (95 to 100%) |
| Pleural fluid | n=77 | 0.89 (0.79 to 1.00) | 80% (28 to 99%) | 81% (70 to 89%) | 22% (6 to 48%) | 98% (90 to 99%) |