Baseline characteristics of the sample
| All | ⩾65 years old | <65 years old | p Value | |
| Number | 122 | 77 (63%) | 45 (37%) | |
| % Men | 62% | 66% | 53% | 0.2 |
| % Current smokers | 29% | 25% | 36% | 0.28 |
| Pack/years, median (IQR) | 40 (25.8) | 40.7 (24.9) | 36 (25) | 0.21 |
| FEV1% | 52.5 (18.5) | 53.6 (16) | 49 (21) | 0.2 |
| PaO2 (kPa) | 9.2 (1.4) | 9.1 (1) | 9.2 (1.3) | 0.7 |
| PaCO2 (kPa) | 5.2 (0.58) | 5.1 (0.5) | 5.3 (0.7) | 0.08 |
| BMI (kg/m2) | 27.5 (5.8) | 27.8 (5.2) | 27.1 (6.7) | 0.6 |
| FFMI (kg/m2) | 17.9 (3.3) | 18.1 (3.1) | 17.7 (3.8) | 0.5 |
| MRC median (IQR) | 1 (1) | 1 (1) | 2 (2) | 0.059 |
| CES-D median (IQR) | 10 (12) | 8 (10) | 12 (12) | 0.006 |
| SGRQ total score | 46 (20) | 42 (17.8) | 54 (21.9) | 0.002 |
| Symptoms domain | 55.4 (23.1) | 52 (21) | 61 (25) | 0.04 |
| Activity domain | 62.4 (27) | 56.7 (25) | 72 (27) | 0.003 |
| Impact domain | 35.1 (19.7) | 31 (17) | 42.3 (22) | 0.004 |
Mean values and SDs are shown unless otherwise noted.
BMI, body mass index; CES-D, Center for Epidemiologic Studies Depression scale; FEV1%, forced expiratory volume over 1 s of predicted; FFMI, fat-free mass index; IQR, interquartile range; MRC, Medical Research Council dyspnoea scale; PaCO2, arterial carbon dioxide pressure; PaO2, arterial oxygen partial pressure; SGRQ, St George’s Respiratory Questionnaire.