Sensitivity, specificity, positive and negative predictive and likelihood ratio values of the Lab-Score, WBC, CRP and PCT for SBI detection
| Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | LR+ (95% CI) | LR– (95% CI) | |
|---|---|---|---|---|---|---|
| Lab-score*(3) (n=406) | 86 (77 to 92) | 83 (79 to 87) | 60 (51 to 68) | 95 (92 to 97) | 5.1 (3.9 to 6.6) | 0.17 (0.10 to 0.28) |
| <3 months (n=106) | 78 (59 to 89) | 90 (81 to 95) | 72 (54 to 85) | 92 (84 to 96) | 7.7 (3.9 to 15.3) | 0.25(0.12 to 0.50) |
| 3–12 months (n=138) | 79 (62 to 90) | 85 (78 to 91) | 59 (43 to 73) | 94 (87 to 97) | 5.4 (3.3 to 8.8) | 0.24(0.12 to 0.50) |
| >12 months (n=162) | 97 (86 to 100) | 77 (69 to 84) | 55 (43 to 67) | 99 (94 to 100) | 4.2 (3.1 to 5.8) | 0.04(0.01 to 0.25) |
| WBC*(15 000 cells/mm3) | 52 (42 to 62) | 75 (70 to 80) | 38 (30 to 47) | 84 (80 to 88) | 2.1 (1.6 to 2.7) | 0.64(0.52 to 0.80) |
| CRP*(40 mg/l) | 73 (63 to 81) | 81 (77 to 85) | 53 (45 to 62) | 91 (87 to 94) | 3.8 (3.0 to 5.0) | 0.34(0.24 to 0.47) |
| PCT*(0.5 ng/ml) | 75 (65 to 83) | 76 (71 to 81) | 48 (40 to 56) | 91 (87 to 94) | 3.1 (2.5 to 4.0) | 0.33(0.23 to 0.47) |
↵* Cut-off level.
CRP, C reactive protein; LR, likelihood ratio; NPV, negative predictive value; PCT, procalcitonin; PPV, positive predictive value; WBC, white blood cell count.