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Table 3 Accuracy of the six inflammatory markers and the combined three-marker and three-marker tests in diagnosing bacterial infection in SIRS patients

From: Use of plasma C-reactive protein, procalcitonin, neutrophils, macrophage migration inhibitory factor, soluble urokinase-type plasminogen activator receptor, and soluble triggering receptor expressed on myeloid cells-1 in combination to diagnose infections: a prospective study

Biomarker

Sensitivity (95% CI)a

Specificity (95% CI)a

AUC (95% CI)

Specificity = 0.7

Specificity = 0.8

Positive predictive valueb

Negative predictive valueb

    

Sensitivity (95% CI)

Sensitivity (95% CI)

  

CRP

0.86 (0.78–0.93)

0.60 (0.46–0.73)

0.81 (0.73–0.86)

0.72 (0.62–0.81)

0.67 (0.56–0.76)

0.79

0.73

PCT

0.80 (0.71–0.88)

0.58 (0.44–0.71)

0.72 (0.63–0.79)

0.69 (0.58–0.78)

0.51 (0.41–0.61)

0.80

0.63

Neutrophil count

0.74 (0.64–0.82)

0.64 (0.50–0.76)

0.74 (0.66–0.81)

0.70 (0.60–0.79)

0.59 (0.49–0.69)

0.82

0.57

MIF

0.80 (0.71–0.88)

0.47 (0.34–0.61)

0.63 (0.53–0.72)

0.41 (0.31–0.51)

0.29 (0.20–0.39)

0.73

0.58

sTREM-1

0.82 (0.73–0.89)

0.40 (0.27–0.54)

0.61 (0.52–0.71)

0.36 (0.27–0.47)

0.32 (0.23–0.43)

0.71

0.56

suPAR

0.35 (0.26–0.46)

0.67 (0.53–0.79)

0.50 (0.40–0.60)

0.31 (0.22–0.42)

0.23 (0.15–0.33)

0.65

0.37

3-markerc

0.67 (0.56–0.76)

0.89 (0.78–0.96)

0.84 (0.71–0.91)

0.76 (0.66–0.84)

0.70 (0.60–0.79)

0.91

0.60

6-markerd

0.88 (0.79–0.93)

0.78 (0.65–0.88)

0.88 (0.81–0.92)

0.89 (0.80–0.94)

0.84 (0.76–0.91)

0.88

0.78

  1. aSensitivity and specificity of C-reactive protein (CRP), procalcitonin (PCT) and neutrophil count were computed using the predefined cutoff values of 60 mg/l, 0.25 μg/l and 7.5 × 109 cells/l, respectively. Sensitivity and specificity of macrophage migration inhibitory factor (MIF), soluble triggering receptor expressed on myeloid cells (sTREM)-1, soluble urokinase-type plasminogen activator receptor (suPAR), and the three-marker and six-marker tests were computed using optimal cutoff values determined using Youdens Index. bPositive and negative predictive values were calculated using Youdens Index-determined optimal cutoffs for all markers. The optimal cutoffs were 59 mg/l for CRP, 0.28 μg/l for PCT, 8.5 × 109 cells/l for neutrophil count, 0.81 μg/l for MIF, 3.5 μg/l for sTREM-1, 2.7 μg/l for suPAR, 6.1 for the three-marker test and 4.1 for the six-marker test. cThree-marker test = 0.160 × neutrophil count + 0.981 × log(CRP) + 0.107 × log(PCT). dSix-marker test = -0.551 × log(suPAR) + 0.254 × log(sTREM-1) + 0.416 × log(MIF) + 0.098 × neutrophils + 0.639 × log(CRP) + 0.201 × log(PCT). AUC, area under the receiver operating characteristic curve; CI confidence interval.