Table 3. Sensitivity and specificity parameters.
| Test | AUC | Sensivity | Specificy | PPV | NPV |
|---|---|---|---|---|---|
| TMHT | 0.573 | 70% | 70% | 17% | 85% |
| Thyromental distance | 0.623 | 50% | 36% | 24% | 93% |
| Sternomental distance | 0.535 | 60% | 41% | 19% | 87% |
| Circuit neck | 0.707 | 67% | 79% | 33% | 88% |
| Cormack-Lehane grade | 0.801 | 65% | 92% | 62% | 93% |
| Mallampati grade | 0.563 | 25% | 87% | 26% | 86% |
Simple linear regression analysis between TMHT height and thyromental height (R = 0.334, P<0.001) and between TMHT height and sternomental height (R = 0.129, P = 0.070) are presented in Fig 6.