Table 4.

Validity indexes for ‘standard airway predictors’ and ‘new airway predictors’ to predict the occurrence of difficult laryngoscopy

	MMT	TMD	SMD	NM	MO	Dentition	RHTMD	TMHT	ULBT
TP	14	28	25	13	4	16	27	27	10
FP	15	26	29	9	4	14	45	24	0
FN	21	7	10	22	31	19	8	8	25
TN	90	79	76	96	101	91	60	81	105
Sensitivity	40	80	71.42	37.14	11.42	45.71	77.14	77.14	28.57
Specificity	85.71	75.23	72.38	91.42	96.19	86.66	57.14	77.14	91.30
PPV	48.27	51.55	46.29	59.09	50	53.33	37.5	52.94	100
NPV	81.08	91.86	88.37	81.35	76.51	82.72	88.23	91.01	77.77
Accuracy	74.28	76.42	72.14	77.85	75	76.42	62.14	77.14	82.14
Odds ratio	4	12.15	6.5	6.30	3.15	5.4	4.5	11.3	86.88
LR	2.55	3.23	2.59	4.33	3	3.43	1.8	3.37	3.28
RR	2.8	6.37	3.98	3.26	2.12	3.08	3.18	5.88	5.2

PPV - Positive Predictive Value; NPV - Negative Predictive Value; LR - Likelihood Ratio; RR - Relative Risk; MMT - Modified Mallampati Test; TMD - Thyromental Distance; SMD - Sternomental Distance; NM - Neck Movement; MO - Mouth Opening; ULBT - Upper Lip Bite Test; RHTMD - Ratio of Height to Thyromental Distance; TMHT - Thyromental Height Test