Patients’ characteristics in the PAC-COPD (Phenotype and Course of Chronic Obstructive Pulmonary Disease) and ICE COLD ERIC (International Collaborative Effort on Chronic Obstructive Lung Disease: Exacerbation Risk Index Cohorts) cohorts at recruitment
| PAC-COPD | ICE COLD ERIC | |
| Patients | 210 | 226 |
| Anthropometric and clinical data | ||
| Male | 195 (92.9) | 135 (60.0) |
| Age years | 67.5±8.2 | 65.7±9.5 |
| Active smoker | 74 (35.2) | 80 (35.4) |
| Physical activity YPAS scale kcal·week−1 | 6056 (3345–9085) | |
| Physical activity LAPAQ-Total score | 13 (9–15) | |
| SGRQ-Total score | 31.2 (22.2–44.1) | |
| CRQ score (mean of four domains) | 5.2 (4.4–6.0) | |
| HADS-Anxiety score | 4 (2–7) | 4 (2–7) |
| HADS-Depression score | 3 (1–5) | 3 (2–6) |
| Charlson index of comorbidity | 2 (1–2) | |
| mMRC dyspnoea score | 2 (2–3) | 1 (1–3) |
| Respiratory frequency breaths·min−1 | 18 (16–20) | |
| Lung function | ||
| Post-bronchodilator FEV1 % pred | 53.5±16.6 | 56.6±16.9 |
| Airflow limitation severity# | ||
| Mild (FEV1 ≥80%) | 13 (6.2) | 10 (4.4) |
| Moderate (FEV1 50– <80%) | 104 (49.5) | 139 (61.5) |
| Severe (FEV1 30– <50%) | 79 (37.6) | 61 (27.0) |
| Very severe (FEV1 <30%) | 14 (6.7) | 16 (7.1) |
| IC/TLC % | 31.4±0.9 | |
| IC % pred | 69.5±20.7 | 73.9±20.8 |
| PaO2 mmHg | 74.8±11.3 | |
| Exercise capacity and muscle force | ||
| 6MWD m | 445±84 | |
| Sit-to-stand repetitions n | 19.9±9.7 | |
| VEmax L·min−1 | 42.2±12.7 | |
| Lactic acid mM | 4.8±2.2 | |
| Handgrip muscle force kg | 31.4±8.2 | 31.7±11.6 |
Data are presented as n, n (%), mean±sd or median (interquartile range). YPAS: Yale Physical Activity Survey; LAPAQ: Longitudinal Aging Study Amsterdam Physical Activity Questionnaire; SGRQ: St George's Respiratory Questionnaire; CRQ: Chronic Respiratory Questionnaire; HADS: Hospital Anxiety and Depression Scale; mMRC: modified Medical Research Council; FEV1: forced expiratory volume in 1 s; IC: inspiratory capacity; TLC: total lung capacity; PaO2: arterial oxygen tension; 6MWD: 6-min walk distance; VEmax: maximal ventilation during incremental cycloergometer test. #: according to the criteria of the American Thoracic Society/European Respiratory Society [38].