Characteristics of 128 chronic obstructive pulmonary disease(COPD) patients on long-term oxygen therapy at baseline and by vital status at the end of follow-up
| Overall | Alive | Deceased | p-value | |
| Subjects n | 50 | 78 | ||
| Age yrs | 68.9±9.7 | 66.3±10.6 | 70.7±8.6 | 0.01 |
| Age ≥70 yrs | 62 (48) | 18 (36) | 44 (56) | 0.03# |
| Males | 126 (98) | 50 (100) | 76 (97) | 0.52# |
| BMI kg·m−2 | 25.1±4.5 | 26.5±4.5 | 24.1±4.3 | 0.003 |
| BMI kg·m−2 (%) | 0.01¶ | |||
| ≥30 | 16 (13) | 7 (14) | 9 (12) | |
| 25–29.9 | 47 (37) | 26 (52) | 21 (27) | |
| 20–24.9 | 50 (39) | 12 (24) | 38 (49) | |
| <20 | 15 (12) | 5 (10) | 10 (13) | |
| Smoker (%) | 0.80# | |||
| Current | 15 (12) | 7 (14) | 8 (10) | |
| Past | 107 (83) | 41 (82) | 66 (85) | |
| Never | 6 (5) | 2 (4) | 4 (5) | |
| Pa,O2 kPa | 7.0±0.7 | 7.1±0.7 | 7.0±0.7 | 0.52 |
| Pa,CO2 kPa | 6.3±0.8 | 6.4±0.8 | 6.3±0.8 | 0.79 |
| DA–a,O2 kPa | 5.2±1.0 | 5.1±1.0 | 5.2±1.0 | 0.49 |
| FEV1 L | 0.72±0.27 | 0.74±0.29 | 0.71±0.25 | 0.61 |
| FEV1 % pred | 25.4±8.8 | 25.3±8.8 | 25.6±9.0 | 0.85 |
| FVC L | 1.50±0.60 | 1.52±0.67 | 1.49±0.56 | 0.80 |
| FVC % pred | 37.2±13.2 | 36.9±14.1 | 37.4±12.7 | 0.83 |
| FEV1/FVC | 0.50±0.12 | 0.50±0.12 | 0.50±0.12 | 0.66 |
| Oral corticosteroids | 24 (19) | 6 (12) | 18 (23) | 0.16# |
| Cor pulmonale | 71 (55) | 22 (44) | 49 (63) | 0.04# |
| COPD-related hospitalisations previous year | 0.14¶ | |||
| 0 | 36 (28) | 18 (36) | 18 (23) | |
| 1 | 55 (43) | 20 (40) | 35 (45) | |
| ≥2 | 37 (29) | 12 (24) | 25 (32) | |
| Comorbid conditions, Charlson Index | 0.02¶ | |||
| 0 | 80 (62) | 36 (72) | 44 (56) | |
| 1 | 31 (24) | 11 (22) | 20 (26) | |
| ≥2 | 17 (14) | 3 (6) | 14 (18) |
Data are presented as mean±sd or n (%), unless otherwise stated. Statistical tests used were unpaired t-test, except where indicated by # and ¶ where Fisher's exact test and Mann–Whitney test were used, respectively. BMI: body mass index; Pa,O2: arterial oxygen tension; Pa,CO2: carbon dioxide arterial tension; DA–a,O2: alveolar–arterial oxygen difference; FEV1: forced expiratory volume in one second; % pred: % predicted; FVC: forced vital capacity.