Table 3. Diagnostic Values of Tests ^a.

Tests	Cormack Test Result		Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Accuracy (%)
	a	b
Mallampati test
Class 3, 4	3	119	100	96.2	97.5	100	98.5
Class 1, 2	78	0
Thyromental distance (cm)
< 6.5	3	94	79	96.2	96.9	75.7	86
> 6.5	78	25
Upper lip biting test
Grade 3	39	6	32.8	92.6	86.7	48.4	57
Grades 1, 2	80	75
Mouth opening test (cm)
< 3	81	93	21.8	100	100	46.5	53.5
> 3	0	26
Palm print sign test
Grades 2, 3	12	119	100	85.2	90.8	100	94
Grades 0, 1	69	0
Prayer sign test
Positive	27	119	100	66.7	81.5	100	86.5
Negative	54	0

Abbreviations: PPV, positive predictive value; NPV, negative predictive value.

^a a: Grade 3, 4 (difficult laryngoscopy); b: Grade 1, 2 (easy laryngoscopy).