Table 3 Diagnostic test accuracy of C-reactive protein for diagnosing serious infection
CRP mg/l | Sensitivity (95% CI) | Specificity (95% CI) | Negative Predictive Value (95% CI) | Positive Predictive Value (95% CI) | Negative Likelihood Ratio (95% CI) | Positive Likelihood Ratio (95% CI) |
|---|---|---|---|---|---|---|
10 | 0.90(0.54 to 0.99) | 0.40(0.33 to 0.48) | 0.99(0.92 to 1.00) | 0.07(0.04 to 0.14) | 0.25(0.04 to 1.61) | 1.51(1.19 to 1.91) |
20 | 0.70(0.35 to 0.92) | 0.52(0.45 to 0.59) | 0.97(0.91 to 0.99) | 0.07(0.04 to 0.14) | 0.58(0.22 to 1.51) | 1.45(0.94 to 2.24) |
30 | 0.60(0.27 to 0.86) | 0.63(0.55 to 0.69) | 0.97(0.92 to 0.99) | 0.08(0.03 to 0.17) | 0.64(0.30 to 1.37) | 1.61(0.94 to 2.75) |
50 | 0.50(0.20 to 0.80) | 0.78(0.72 to 0.84) | 0.97(0.92 to 0.99) | 0.11(0.04 to 0.24) | 0.64(0.34 to 1.19) | 2.30(1.17 to 4.51) |
75 | 0.40(0.14 to 0.73) | 0.87(0.81 to 0.91) | 0.97(0.92 to 0.99) | 0.13(0.04 to 0.32) | 0.69(0.42 to 1.15) | 2.97(1.28 to 6.87) |
100 | 0.40(0.14 to 0.73) | 0.93(0.89 to 0.96) | 0.97(0.92 to 0.99) | 0.24(0.08 to 0.50) | 0.64(0.39 to 1.07) | 5.94(2.36 to 14.95) |
150 | 0.20(0.04 to 0.56) | 0.97(0.94 to 0.99) | 0.96(0.92 to 0.98) | 0.29(0.05 to 0.70) | 0.82(0.60 to 1.12) | 7.72(1.70 to 35.00) |
200 | 0.10(0.01 to 0.46) | 0.99(0.96 to 1.00) | 0.96(0.91 to 0.98) | 0.33(0.02 to 0.87) | 0.91(0.74 to 1.12) | 9.65(0.95 to 97.7) |