Predictive values for three different methods determining tube position in head trauma patients (n = 81)
| False (−) | False (+) | True (−) | True (+) | Sensitivity | Specificity | PPV* | NPV† | |
|---|---|---|---|---|---|---|---|---|
| A, McNemar’s test for sensitivity showed: capnometry 1, capnometry 2, capnography > auscultation (p<0.01). B, McNemar’s test for specificity showed: capnometry 1, capnometry 2, capnography > auscultation (p<0.01). C McNemar’s test for positive predictive value showed: capnometry 1, capnometry 2, capnography > auscultation (p<0.01). D, McNemar’s test for negative predictive value showed: capnometry 1, capnometry 2, capnography > auscultation (p<0.01). *Positive predictive value; †negative predictive value. | ||||||||
| Auscultation | 4 | 4 | 8 | 65 | 94 (88–98) | 66 (58–70) | 94 (88–98) | 66 (56–70) |
| Capnometry 1 (initial) | 0 | 0 | 8 | 73 | 100 (95–100) | 100 (97–100) | 100 (92–100) | 100 (90–100) |
| Capnometry 2 (at 7th breath) | 0 | 0 | 8 | 73 | 100 (96–100) | 100 (94–100) | 100 (94–100) | 100 (92–100) |
| Capnography | 0 | 0 | 8 | 73 | 100 (98–100) | 100 (97–100) | 100 (95–100) | 100 (93–100) |
| A | B | C | D | |||||