Group

Sensitivity

Specificity

Positive predictive value

Negative predictive value

Diagnostic accuracy

Observation group (n = 8)

87.50 (7/8)

40.00 (2/5)

77.78 (7/9)

80.00 (4/5)

69.23 (9/13)

Control group (n = 9)

62.50 (5/8)

20.00 (1/5)

55.56 (5/9)

40.00 (2/5)

46.15 (6/13)

χ2

9.045

9.684

10.684

19.557

11.531

P

<0.001

<0.001

<0.001

<0.001

<0.001