Association of prebronchodilator and postbronchodilator spirometric measures with chronic bronchitis, dyspnoea scores, chest CT emphysema and air trapping and distance covered in 6 min walk test
| Prebronchodilator FEV1/FVC <0.7 (PREO) | Postbronchodilator FEV1/FVC <0.7 (POSTO) | |||||
| OR (95% CI) | P value | AIC | OR (95% CI) | P value | AIC | |
| Chronic bronchitis | 2 (1.78 to 2.25) | <0.001 | 8910 | 2.14 (1.9 to 2.41) | <0.001 | 8882 |