Results of linear mixed models analysis for the cohort (change in FEV1 per unit change in covariable)
| Estimated effects of specified increments in covariables: changes in FEV1 (ml) | ||||
| Covariate | Increment or comparison | Change in FEV1 per unit change in covariable | 95% CI | p Value |
| Study centre | Utrecht vs Groningen | +43.5 | −100 to 13.8 | 0.137 |
| Years in study | Plus 1 year | −65.6 | − 69.4 to −61.6 | <0.001 |
| Smoking status | Current vs former | −186.7 | −241.0 to −132.2 | <0.001 |
| Age (years) | Plus 1 year | −36.2 | −41.3 to −31.1 | <0.001 |
| Height (cm) | Plus 1 cm | +38.6 | 34.7 to 42.7 | <0.001 |
| Pack-years | Plus 1 year | −5.16 | −6.62 to −3.68 | <0.001 |
| HU 15th percentile at CT | Decrease of 1 HU | −4.75 | −3.30 to −6.10 | <0.001 |
FEV1, forced expiratory volume in 1 s; HU, Hounsfield Unit.