Table 4 Sensitivity, specificity, PPV, NPV, and accuracy of inflammatory markers
From: Synovial fluid IL-1β appears useful for the diagnosis of chronic periprosthetic joint infection
Parameters | ESR (mm/h) | CRP (mg/L) | SF IL-1β (pg/ml) | SF PMN (%) | SF IL-1β +CRP | SF IL-1β+ PMN% |
|---|---|---|---|---|---|---|
AUC (95%CI) | 0.627 (0.521, 0.725) | 0.712 (0.609, 0.801) | 0.991 (0.945, 1.000) | 0.981 (0.928, 0.998) | / | / |
Cutoff level | 34 | 13 | 312.7 | 69.96 | SF IL-1β>312.7 +CRP>13 | SF IL-1β>312.7+ PMN%>69.96 |
Sensitivity (%) (95%CI) | 54.05 (36.9, 70.5) | 89.19 (74.6, 97.0) | 97.30 (85.8, 99.9) | 94.59 (81.8, 99.3) | 86.49 (70.43, 94.92) | 91.89 (76.98, 97.88) |
Specificity (%) (95%CI) | 78.57 (65.6, 88.4) | 50.00 (36.3, 63.7) | 94.64 (85.1, 98.9) | 92.86 (82.7, 98.0) | 96.43 (86.62, 99.38) | 100 (92.00,100) |
PPV (%) | 62.50 | 54.10 | 92.31 | 89.74 | 94.12 | 100 |
NPV (%) | 72.13 | 87.50 | 98.15 | 96.30 | 91.53 | 94.92 |
Accuracy (%) | 68.82 | 65.59 | 95.70 | 93.55 | 92.47 | 96.77 |