Tracheal measurement | Correlation coefficient (r) for differences in spirometric values* | |||||
| FEV1 | FEV1 (% predicted) | FEV1/FVC | FEF25-75% | FEF25-75% (% predicted) | Peak flow |
Difference in minimumtracheal CSA* | 0.446 (P < 0.05) | 0.418 (P < 0.05) | 0.594 (P < 0.01) | 0.240 (NS) | 0.250 (NS) | 0.397 (P < 0.05) |