Baseline characteristics
| ITT NIV n=101 | ITT controls n=100 | Completers NIV n=54 | Completers controls n=54 | |
|---|---|---|---|---|
| Age (years) | 63.92 (8.6) | 63.5 (7.9) | 61.9 (7.9) | 62.3 (7.9) |
| Gender, n (% female) | 60 (59%) | 58 (58%) | 36 (67%) | 34 (63%) |
| Pack years* | 38 (0–140) | 44 (0–125) | 38 (0–125) | 38 (0–125) |
| BMI (kg/m2) | 24.6 (5.4) | 24.8 (6.3) | 24.7 (5.5) | 24.2 (5.3) |
| LTOT, n (%) | 76 (75%) | 78 (78%) | 38 (70%) | 37 (69%) |
| Invasive, n (%)† | 13 (13%) | 12 (12%) | 7 (13%) | 10 (19%) |
| Duration ventilation*‡ (days) | 5.0 (1–19) | 5.0 (1–24) | 5.5 (2–19) | 5.0 (1–23) |
| Admissions* (year−1) | 2.0 (1–9) | 2.0 (1–10) | 2.0 (1–9) | 1.0 (1–6) |
| Total admission days/patient* (year−1) | 28.5 (8–108) | 22.0 (6–115)§ | 29.0 (8–100) | 20.0 (7–115)§ |
| Rehabilitation, n (%) | 50 (50%) | 51 (51%) | 25 (46%) | 30 (56%) |
| FEV1 (L) | 0.67 (0.23) | 0.65 (0.23) | 0.70 (0.24) | 0.70 (0.25) |
| FEV1 (% pred) | 25.6 (7.8) | 25.7 (8.6) | 26.9 (7.7) | 27.6 (8.6) |
| FVC (% pred) | 64.3 (19.8) | 63.6 (17.0) | 65.7 (18.4) | 67.8 (17.1) |
| FEV1 to FVC (%) | 32.5 (9.0) | 33.0 (9.5) | 33.9 (9.6) | 33.8 (9.7) |
| PaCO2¶ (kPa) | 7.9 (1.2) | 7.7 (1.3) | 8.0 (1.2) | 7.5 (1.0) |
| PaO2¶ (kPa) | 7.9 (2.1) | 7.5 (1.7) | 8.3 (1.6) | 7.9 (1.8) |
| Medication, n (%) | ||||
| Inhaled corticosteroid | 86 (85%) | 84 (84%) | 43 (81%) | 48 (89%) |
| Oral corticosteroids | 53 (53%) | 38 (38%) | 27 (50%) | 17 (32%) |
| Beta agonists | 98 (97%) | 97 (97%) | 52 (98%) | 53 (98%) |
| Anticholinergics | 94 (93%) | 94 (94%) | 49 (93%) | 52 (96%) |
| Theophylline | 37 (37%) | 27 (27%) | 20 (38%) | 16 (30%) |
Data presented as mean (SD) unless otherwise stated.
*Pack years, duration ventilation and admissions for respiratory causes including index admission in median (range).
†Invasive ventilation during acute respiratory failure. Other patients received NIV.
‡Ventilation during acute respiratory failure of index admission.
§p<0.05 significant difference compared with NIV.
¶While breathing room air (in both groups blood samples from 21 patients were taken with oxygen as they were not able to come of oxygen).
% pred, % predicted; BMI, body mass index; Controls, standard treatment; ITT, intention-to-treat; LTOT, long-term oxygen therapy; n, numbers for analysis; NIV, non-invasive positive pressure ventilation; PaCO2, arterial carbon dioxide pressure; PaO2, arterial oxygen pressure.