Table 3 Predictive values for ULBT and MMT to predict difficult intubation according to CL classification

Accuracy (%)

81.33

66.22

71.11

Sensitivity (%)

11.59

62.32

53.62

Specificity (%)

93.96

69.29

74.28

PPV (%)

25.81

26.88

27.41

NPV (%)

85.44

91.03

89.84

Likelihood ratio of a

1.92

2.03

2.08

 Likelihood ratio of a

0.94

0.54

0.62

 Kappa

0.072

0.205

0.039

 Youden index

0.056

0.316

0.279

 P-value

0.303

<0.001*

<0.001*

 Area under ROC curve

0.539

0.684

0.684