Baseline characteristics from a 3-year longitudinal study to phenotype subjects with COPD: the FOOTPRINTS study

Respiratory Research

Table 1 Subject demographics

	EwAL	GOLD 1	GOLD 2	GOLD 3	A1ATD
Enrolled subjects, n	62	123	130	129	19
Per-protocol subjects, n	61	122	127	127	19
Male, n (%)	38 (62.3)	85 (69.7)	76 (59.8)	79 (62.2)	16 (84.2)
Age, years	53.9 (6.8)	62.0 (6.2)	61.8 (5.4)	62.9 (5.6)	52.8 (9.0)
BMI, kg/m²	26.48 (2.74)	27.16 (3.43)	26.66 (4.07)	26.33 (4.32)	25.06 (3.87)
Smoking history, pack-years	32.9 (14.6)	41.5 (17.6)	46.1 (18.2)	49.2 (21.6)	25.2 (12.3)
Subjects with ≥ 1 comorbidities^a, n (%)^b	NA	84 (68.9)	108 (85.0)	97 (76.4)	14 (73.7)
Subjects with ≥ 3 comorbidities^a, n (%)^b	NA	33 (27.0)	50 (39.4)	51 (40.2)	4 (21.1)
History of COPD exacerbations, n (%)
Yes No Missing	NA NA NA	30 (24.6) 88 (72.1) 4 (3.3)	48 (37.8) 79 (62.2) 0 (0.0)	71 (55.9) 55 (43.3) 1 (0.8)	12 (63.2) 7 (36.8) 0 (0.0)

Age, BMI and smoking history are mean (SD). A1ATD subjects are not included in the GOLD 1–3 columns
A1ATD alpha-1-antitrypsin deficiency, BMI body mass index, COPD chronic obstructive pulmonary disease, EwAL ex-smokers without airflow limitation, GOLD Global Initiative for Chronic Obstructive Lung Disease, NA not assessed, SD standard deviation
^aPneumonia, pulmonary fibrosis, chronic respiratory failure, asthma–chronic pulmonary disease overlap syndrome, obstructive sleep apnoea, bronchiectasis, pleural effusion, lung cancer, angina pectoris, ischaemic heart disease (incl. myocardial infarction), systemic arterial hypertension, hypotension, aneurysm, syncope, cardiac arrhythmia, heart failure, cerebrovascular disease, diabetes mellitus, obesity, hyper-/dyslipidaemia, cholecystitis, cholecystolithiasis, colitis, gastroesophageal reflux disease, dementia, cognitive impairment, depression, anxiety, osteoarticular disorders
^bData were missing for four subjects in the GOLD 1 group, one in GOLD 3, and one in the A1ATD group

ISSN: 1465-993X