TABLE 4

Clinical and physiological factors associated with pro-surfactant protein B levels^#

Parameter	β coefficient	se	p-value	R²
CT emphysema score ⩾4	0.132	0.040	0.001	0.006
Smoking pack-years	0.003	<0.001	<0.001	0.002
Current smoking	0.263	0.018	<0.001	0.074
Age years	0.014	0.003	<0.001	0.001
Male	0.033	0.017	0.049	0.003