TABLE 2 Characteristics of individuals with and without chronic mucus hypersecretion (CMH) in NELSON subjects without chronic obstructive pulmonary disease (COPD) and in the LifeLines cohort

	NELSON-non-COPD			LifeLines
	CMH	No CMH	p-value	CMH	No CMH	p-value
Subjects n (%)	342 (25.4)	1006 (74.6)		130 (5.3)	2313 (94.7)
Age years	59.6±5.3	59.8±5.3	0.61	47.2±10.7	47.4±9.7	0.82
Females %	0	0		46.2	53.4	0.11
Smoking pack-years	38.0 (22–140)	34.2 (20–133)	0.029	15.5 (5–84)	13.0 (5–75)	<0.001
Current smokers %	70.8	45.2	<0.001	60.0	43.1	<0.001
FEV₁ % predicted	105.2±13.1	107.6±13.4	0.003	100.5±14.2	103.6±12.8	0.008
FEV₁/FVC %	78.0±4.6	78.1±4.5	0.62	77.1±4.4	78.0±4.8	0.040

Data are presented as mean ± sd or median (range), unless otherwise stated. FEV₁: forced expiratory volume in 1 s; FVC: forced vital capacity.