. 2022 Nov 18;182(2):941–947. doi: 10.1007/s00431-022-04690-7

Table 1.

Performance of CRP, PCT and viremia to discriminate patients with or without serious bacterial infection

	Sensitivity % (n/N) 95% CI	Specificity % (n/N) 95% CI	Positive predictive value % (n/N) 95% CI	Negative predictive value % (n/N) 95% CI	Positive likelihood ratio 95% CI	Negative likelihood ratio 95% CI
Full dataset
CRP ≥ 40 mg/l	65.0 (13/20) 40.8 − 84.6	74.8 (86/115) 65.8 − 82.4	31.0 (13/42) 17.6 − 47.1	92.5 (86/93) 85.1 − 96.9	2.58 1.64 − 4.04	0.47 0.26 − 0.86
PCT ≥ 0.5 ng/ml	55.0 (11/20) 31.5 − 76.9	75.0 (84/112) 65.9 − 82.7	28.2 (11/39) 15.0 − 44.9	90.3 (84/93) 82.4 − 95.5	2.20 1.32 − 3.66	0.60 0.37 − 0.99
No viremia	90.0 (18/20) 68.3 − 98.8	39.1 (45/115) 30.2 − 48.7	20.5 (18/88) 12.6 − 30.4	95.7 (45/47) 85.5 − 99.5	1.48 1.20 − 1.82	0.26 0.07 − 0.97
No HEV viremia	95.0 (19/20) 75.1 − 99.9	15.7 (18/115) 9.5 − 23.6	16.4 (19/116) 10.2 − 24.4	94.7 (18/19) 74.0 − 99.9	1.13 0.99 − 1.28	0.32 0.04 − 2.26
No HHV-6 viremia	95.0 (19/20) 75.1 − 99.9	12.2 (14/115) 6.8 − 19.6	15.8 (19/120) 9.8 − 23.6	93.3 (14/15) 68.1 − 99.8	1.08 0.96 − 1.22	0.41 0.06 − 2.95
No HPeV viremia	100.0 (20/20) 83.2 − 100.0	7.0 (8/115) 3.1 − 13.2	15.7 (20/127) 9.9 − 23.3	100.0 (8/8) 63.1 − 100.0	1.08 1.02 − 1.13	-
No AdV viremia	100.0 (20/20) 83.2 − 100.0	6.1 (7/115) 2.5 − 12.1	15.6 (20/128) 9.8 − 23.1	100.0 (7/7) 59.0 − 100.0	1.07 1.02 − 1.12	-
Age < 3 months
CRP ≥ 40 mg/l	53.8 (7/13) 25.1 − 80.8	90.9 (60/66) 81.3 − 96.6	53.8 (7/13) 25.1 − 80.8	90.9 (60/66) 81.3 − 96.6	5.92 2.37 − 14.77	0.51 0.28 − 0.92
PCT ≥ 0.5 ng/ml	46.2 (6/13) 19.2 − 74.9	86.4 (57/66) 75.7 − 93.6	40.0 (6/15) 16.3 − 67.7	89.1 (57/64) 78.8 − 95.5	3.38 1.45 − 7.88	0.62 0.37 − 1.04
No viremia	92.3 (12/13) 64.0 − 99.8	34.8 (23/66) 23.5 − 47.6	21.8 (12/55) 11.8 − 35.0	95.8 (23/24) 78.9 − 99.9	1.42 1.12 − 1.79	0.22 0.03 − 1.49
Age ≥ 3 months
CRP ≥ 40 mg/l	85.7 (6/7) 42.1 − 99.6	53.1 (26/49) 38.3 − 67.5	20.7 (6/29) 8.0 − 39.7	96.3 (26/27) 81.0 − 99.9	1.83 1.19 − 2.79	0.27 0.04 − 1.68
PCT ≥ 0.5 ng/ml	71.4 (5/7) 29.0 − 96.3	58.7 (27/46) 43.2 − 73.0	20.8 (5/24) 7.1 − 42.2	93.1 (27/29) 77.2 − 99.2	1.73 0.97 − 3.09	0.49 0.15 − 1.61
No viremia	85.7 (6/7) 42.1 − 99.6	44.9 (22/49) 30.7 − 59.8	18.2 (6/33) 7.0 − 35.5	95.7 (22/23) 78.1 − 99.9	1.56 1.05 − 2.31	0.32 0.05 − 2.01

Sensitivity
% (n/N)
95% CI

Specificity
% (n/N)
95% CI

Positive
predictive value
% (n/N)
95% CI

Negative
predictive value
% (n/N)
95% CI

Positive
likelihood ratio
95% CI

Negative
likelihood ratio
95% CI

Full dataset

CRP ≥ 40 mg/l

65.0 (13/20)

40.8 − 84.6

74.8 (86/115)

65.8 − 82.4

31.0 (13/42)

17.6 − 47.1

92.5 (86/93)

85.1 − 96.9

2.58

1.64 − 4.04

0.47

0.26 − 0.86

PCT ≥ 0.5 ng/ml

55.0 (11/20)

31.5 − 76.9

75.0 (84/112)

65.9 − 82.7

28.2 (11/39)

15.0 − 44.9

90.3 (84/93)

82.4 − 95.5

2.20

1.32 − 3.66

0.60

0.37 − 0.99

No viremia

90.0 (18/20)

68.3 − 98.8

39.1 (45/115)

30.2 − 48.7

20.5 (18/88)

12.6 − 30.4

95.7 (45/47)

85.5 − 99.5

1.48

1.20 − 1.82

0.26

0.07 − 0.97

No HEV viremia

95.0 (19/20)

75.1 − 99.9

15.7 (18/115)

9.5 − 23.6

16.4 (19/116)

10.2 − 24.4

94.7 (18/19)

74.0 − 99.9

1.13

0.99 − 1.28

0.32

0.04 − 2.26

No HHV-6 viremia

95.0 (19/20)

75.1 − 99.9

12.2 (14/115)

6.8 − 19.6

15.8 (19/120)

9.8 − 23.6

93.3 (14/15)

68.1 − 99.8

1.08

0.96 − 1.22

0.41

0.06 − 2.95

No HPeV viremia

100.0 (20/20)

83.2 − 100.0

7.0 (8/115)

3.1 − 13.2

15.7 (20/127)

9.9 − 23.3

100.0 (8/8)

63.1 − 100.0

1.08

1.02 − 1.13

No AdV viremia

100.0 (20/20)

83.2 − 100.0

6.1 (7/115)

2.5 − 12.1

15.6 (20/128)

9.8 − 23.1

100.0 (7/7)

59.0 − 100.0

1.07

1.02 − 1.12

Age < 3 months

CRP ≥ 40 mg/l

53.8 (7/13)

25.1 − 80.8

90.9 (60/66)

81.3 − 96.6

53.8 (7/13)

25.1 − 80.8

90.9 (60/66)

81.3 − 96.6

5.92

2.37 − 14.77

0.51

0.28 − 0.92

PCT ≥ 0.5 ng/ml

46.2 (6/13)

19.2 − 74.9

86.4 (57/66)

75.7 − 93.6

40.0 (6/15)

16.3 − 67.7

89.1 (57/64)

78.8 − 95.5

3.38

1.45 − 7.88

0.62

0.37 − 1.04

No viremia

92.3 (12/13)

64.0 − 99.8

34.8 (23/66)

23.5 − 47.6

21.8 (12/55)

11.8 − 35.0

95.8 (23/24)

78.9 − 99.9

1.42

1.12 − 1.79

0.22

0.03 − 1.49

Age ≥ 3 months

CRP ≥ 40 mg/l

85.7 (6/7)

42.1 − 99.6

53.1 (26/49)

38.3 − 67.5

20.7 (6/29)

8.0 − 39.7

96.3 (26/27)

81.0 − 99.9

1.83

1.19 − 2.79

0.27

0.04 − 1.68

PCT ≥ 0.5 ng/ml

71.4 (5/7)

29.0 − 96.3

58.7 (27/46)

43.2 − 73.0

20.8 (5/24)

7.1 − 42.2

93.1 (27/29)

77.2 − 99.2

1.73

0.97 − 3.09

0.49

0.15 − 1.61

No viremia

85.7 (6/7)

42.1 − 99.6

44.9 (22/49)

30.7 − 59.8

18.2 (6/33)

7.0 − 35.5

95.7 (22/23)

78.1 − 99.9

1.56

1.05 − 2.31

0.32

0.05 − 2.01

CRP C-reactive protein, PCT procalcitonin, CI confidence interval, HEV human enterovirus, HHV-6 human herpesvirus type 6, HPeV human parechovirus, AdV adenovirus