Table 1. Characteristics of study participants.

Characteristic	Patient group (n = 776)		Control group (n = 715)		p-value
	n	(%)	n	(%)
Age, median (range)	64 (20–88)		50 (21–94)		<0.001†
Age (years)   <60   ≥60	291 485	37.5 62.5	614 101	85.9 14.1	<0.001†
Sex   Female   Male	433 343	55.8 44.2	398 317	55.7 44.3	0.958
BMI, median (range)	27.1 (16–48)		26.1 (18–40)		0.943
BMI   <25 kg/m2   ≥25 kg/m2	187 422	30.7 69.3	118 269	30.5 69.5	0.943
Smoking   No   Ex-smoker   Yes	436 165 135	59.3 22.4 18.3	428 16 149	72.2 2.7 25.1	<0.001†
Diabetes mellitus   No   Yes	635 141	81.8 18.2	666 49	93.1 6.9	<0.001†
Hypertension   No   Yes	513 263	66.1 33.9	616 99	86.2 13.8	<0.001†
Coronary disease   No   Yes	710 66	91.5 8.5	698 17	97.6 2.4	<0.001†
Chronic renal failure   No   Yes	759 17	97.8 2.2	714 1	99.9 0.1	<0.001†
Chronic liver disease   No   Yes	761 15	98.1 1.9	709 6	99.2 0.8	0.081
Rheumatological disease   No   Yes	766 10	98.7 1.3	707 8	98.9 1.1	0.816
Psychiatric disease   No   Yes	762 14	98.2 1.8	713 2	99.7 0.3	0.004†
Respiratory disease   No   Yes	741 35	95.5 4.5	703 12	98.3 1.7	0.002†
Other   No   Yes	731 45	94.2 5.8	686 29	95.9 4.1	0.152

^†Statistically significant results.