TABLE 1

Demographics and baseline characteristics

	COPD	Non-COPD	p-value^#	COPD		Non-COPD		p-value^¶
	COPD	Non-COPD	p-value^#	Mild (GOLD 1)	Moderate (GOLD 2)	Smokers	Never-smokers	p-value^¶
Subjects n	659	784		397	262	449	335
Age years	67.2±10.1	65.9±9.6	0.019	68.0±9.8^§,f	65.9±10.3^f	65.6±9.4^§	66.3±9.8	0.008
Male	404 (61.3)	412 (52.6)	<0.001	259 (65.2)	145 (55.3)	262 (58.4)	150 (44.8)	<0.001
BMI	27.2±4.8	27.8±5.2	0.122	26.9±4.4^§	27.6±5.2	28.1±5.2^§	27.4±5.2	0.017
Never-smokers	190 (28.8)	335 (42.7)	<0.001	132 (33.2)^§	58 (22.1)^§	0	335 (100.0)	<0.001
Former smokers	352 (53.4)	346 (44.1)	<0.001	212 (53.4)^§	140 (53.4)^f	346 (77.1)^§,f	0	<0.001
Current smokers	117 (17.8)	103 (13.1)	0.015	53 (13.4)^§,f	64 (24.4)^f	103 (22.9)^§	0	<0.001
GOLD1	397 (60.2)	0	–	397 (100.0)	0	0	0	–
GOLD2	262 (39.8)	0	–	0	262 (100.0)	0	0	–
Self-reported physician-diagnosed asthma	202 (30.7)	124 (15.8)	<0.001	93 (23.4)^§	109 (41.6)^§,f	76 (16.9)^f	48 (14.3)^§	<0.001
Any respiratory medication prescription⁺	215 (32.6)	85 (10.8)	<0.001	81 (20.4)^§,f	134 (51.1)^§,f	54 (12.0)^f	31 (9.3)^§	<0.001
Emphysema score	1.8±3.1	0.5±1.3	<0.001	1.4±2.5^§	2.3±3.7^§	0.7±1.5^§	0.2±0.7^§	<0.001
RV/TLC %	42±9.6	37.5±8.2	<0.001	39.2±8.7^f	46.3±9.4^§,f	37.4±8.0^f	37.6±8.5^§	<0.001
Chronic bronchitis	112 (17.0)	99 (12.6)	0.0019	44 (11.1)^¶¶	68 (26.0)^f,##,¶¶	69 (15.4)^##	30 (9.0)^f	<0.001

Data are presented as n, mean±sd or n (%), unless otherwise stated. BMI: body mass index; COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; ICS: inhaled corticosteroids; LABA: long-acting β₂-agonist; LAMA: long-acting muscarinic antagonist; RV/TLC: residual volume/total lung capacity; SABA: short-acting β₂-agonist; SAMA: short-acting muscarinic antagonist. ^#: p-values were obtained by performing Chi-squared or Fisher's exact test for category variables, and t-test (normal distribution) or Mann–Whitney U tests (non-normal distribution) for continuous variables. ^¶: p-values were obtained by performing Chi-squared or Fisher's exact tests for category variables, and analysis of variance (normal distribution) or Kruskal–Wallis test (not normal distribution) for continuous variables. ⁺: Respiratory medicines included were: SAMA/SABA; LABA±SAMA/SABA; LAMA±SAMA/SABA; LAMA+LABA±SAMA/SABA; ICS±SAMA/SABA; LABA+ICS±SAMA/SABA; LAMA+ICS±SAMA/SABA; LAMA+LABA+ICS±SAMA/SABA. ^{§, f, ##, ¶¶}: Values with the same symbol are significantly different from each other after Tukey adjustment for multiple comparisons (p<0.05). Bold indicates statistical significance.