| LTOT | NIV + LTOT | NIV + LTOT | |
| Baseline | Baseline | NIV treatment | |
| Total sleep time (min) | 243 (226 to 260) | 249 (231 to 267) | 252 (234 to 271) |
| Sleep efficiency (%) | 61.0 (56.8 to 65.2) | 59.6 (55.4 to 63.8) | 59.7 (55.7 to 63.7) |
| % NREM | 85.0 (83.0 to 87.0) | 86.7 (84.6 to 88.8) | 82.6 (80.4 to 84.8)* |
| % REM | 15.2 (13.2 to 17.3) | 13.3 (11.2 to 15.4) | 17.5 (15.3 to 19.7)* |
| Apnoea-hypopnoea index (events/h) | 6.1 (4.8 to 7.5) | 4.5 (3.4 to 5.6) | 2.8 (1.6 to 4.0)* |
| Tcco2 sleep increase (mm Hg) | 18.8 (16.5 to 21.0) | 16.5 (14.7 to 18.3) | 12.6 (10.9 to 14.3)* |
| IPAP (cm H2O) | 12.9 (12.5 to 13.4) | ||
| EPAP (cm H2O) | 5.1 (4.8 to 5.3) |
Values are mean (95% CI).
*p<0.05 compared with corresponding baseline values.
EPAP, expiratory partial airway pressure; IPAP inspiratory partial airway pressure; LTOT, long-term oxygen therapy; NIV + LTOT, nocturnal non-invasive ventilation plus long-term oxygen therapy; % NREM, non-rapid eye movement sleep expressed as a percentage of total sleep time; % REM, rapid eye movement sleep expressed as a percentage of total sleep time; Tcco2, transcutaneous partial pressure of carbon dioxide.