| Baseline | 6 months | 12 months | ||
| Paco2 (mm Hg) | LTOT | 54.2 (52.0 to 56.4) | 55.1 (52.1 to 58.1) | 52.2 (49.5 to 54.9) |
| n = 45 | n = 43 | n = 29 | ||
| NIV+LTOT | 54.1 (51.7 to 56.5) | 52.9 (50.5 to 55.3) | 53.2 (50.6 to 55.8) | |
| n = 54 | n = 44 | n = 43 | ||
| FEV1.0 (% pred) | LTOT | 23.9 (21.9 to 25.9) | 23.4 (21.4 to 25.4) | 26.3 (24.1 to 28.5) |
| n = 51 | n = 47 | n = 38 | ||
| NIV+LTOT | 25.3 (22.3 to 28.3) | 24.9 (21.7 to 28.1) | 24.1 (21.1 to 27.1) | |
| n = 58 | n = 56 | n = 47 |
Values are mean (95% CI). Sample sizes are unequal because patient data were censored if it was not possible to obtain measurements under the same conditions (FEV1.0 prebronchodilator; arterial blood gases on room air or on oxygen at the same flow rate) on at least two of three occasions.
FEV1.0, forced expiratory volume in 1 s; LTOT, long-term oxygen therapy; NIV + LTOT, nocturnal non-invasive ventilation plus long-term oxygen therapy; Paco2, arterial carbon dioxide tension.