Table 4.
Operating characteristics for a combination of markers to predict appendicitis
| Author | Subjects | Combination of markers | Sensitivity (%) | Specificity (%) | +LR | −LR | Study type | Comments |
|---|---|---|---|---|---|---|---|---|
| Deballon et. al41 (2008) | 135 | CRP ≥ 6 mg/L and WBC ≥ 9.6 × 103 cells/mm3 | 86 | 37 | 1.37 | 0.38 | Prospective | |
| Sengupta et. al33 (2009) | 98 | CRP ≥ 10 mg/L and WBC ≥ 11 × 103 cells/mm3 | 50 | 90 | 5 | 0.56 | Prospective | NPV: 88% |
| CRP ≥ 10 mg/L OR WBC ≥ 11 × 103 cells/mm3 | 100 | 51 | 2.04 | 0 | NPV: 100% | |||
| Shaw et. al45 (2011) | 297 | Hospital Centre A: | Retrospective | Study performed at 2 different hospitals. Results listed for each hospital | ||||
| CRP ≥ 10 mg/L and WBC ≥ 11 × 103 cells/mm3 and PMN Count ≥7.5 × 109/L | 46 | 89 | 4.18 | 0.61 | ||||
| CRP ≥ 10 mg/L or WBC ≥ 11 × 103 cells/mm3 or PMN Count ≥7.5 × 109/L | 94 | 60 | 2.35 | 0.1 | ||||
| Hospital Centre B: | ||||||||
| CRP ≥ 10 mg/L and WBC ≥ 11 × 103 cells/mm3 and PMN Count ≥7.5 × 109/L | 53 | 77 | 2.30 | 0.61 | ||||
| CRP ≥ 10 mg/L or WBC ≥ 11 × 103 cells/mm3 or PMN Count ≥7.5 × 109/L | 92 | 64 | 2.56 | 0.13 | ||||
| Van Dieijen-Visser et. al55 (1991) | 258 | CRP ≥ 12 mg/L and WBC ≥ 10 × 103 cells/mm3 | 56 | 93 | 8 | 0.47 | Retrospective | |
| CRP ≥ 12 mg/L or WBC ≥ 10 × 103 cells/mm3 | 97 | 55 | 2.16 | 0.05 | PPV: 94% | |||
| CRP ≥ 12 mg/L and WBC ≥ 10 × 103 cells/mm3 and PMN Ratio > 70% | 22 | 99 | 22 | 0.79 | NPV: 98% | |||
| CRP ≥ 12 mg/L or WBC ≥ 10 × 103 cells/mm3 or PMN Ratio > 70% | 99 | 50 | 1.98 | 0.02 | ||||
| Yang et. al47 (2006) | 897 | WBC ≥ 10.4 × 103 cells/mm3 or PMN Ratio > 74% | 95 | 17 | 1.14 | 0.29 | Retrospective | |
| CRP ≥ 8 mg/L or WBC ≥ 10.4 × 103 cells/mm3 | 98 | 12 | 1.11 | 0.17 | ||||
| CRP ≥ 8 mg/L or WBC ≥ 10.4 × 103 cells/mm3 or PMN Ratio > 74% | 99 | 6 | 1.05 | 0.17 |
CRP; C-reactive protein; WBC; white blood cells; PMN, polymorphonoculear leukocytes; LR, likelihood ratio; PPV, positive predictive value; NPV, negative predictive value