Independent clinical characteristics associated with the presence of early chronic obstructive pulmonary disease (COPD) identified by multiple regression logistic analysis (by odds ratio value)
| OR (95% CI) | p-value | ||
| Hospital admission for respiratory disease before the age of 5 years | 9.292 (2.57–36.10) | <0.001 | |
| Emergency room visits due to respiratory reasons | 9.160 (1.43–180.74) | <0.05 | |
| mMRC ≥2 | 2.336 (1.36–4.14) | <0.01 | |
| Packs-years | 1.030 (1.00–1.06) | <0.05 | |
| KCO % ref. | 0.950 (0.92–0.98) | <0.001 | |
| Active worker | 0.391 (0.16–0.99) | <0.05 |
mMRC: modified Medical Research Council scale; KCO: transfer coefficient of the lung for carbon monoxide; % ref.: % of reference value.