Population characteristics at noninvasive ventilation (NIV) initiation depending on adherence assessment at day 30
| Patient characteristics at initiation | Total | Adherence >4 h | Adherence <4 h | p-value |
| Anthropometric data | ||||
| Patients | 233 | 153 (66) | 80 (34) | |
| Age (years) | 68±11 | 68.1±10.6 | 68±11.2 | 0.907 |
| Male | 148 (63) | 101 (66) | 47 (59) | 0.274 |
| BMI (kg·m−2) | 24±5 | 24.4±4.64 | 23±4.13 | 0.028 |
| Smoking greater than 20 pack-years | 21 (9) | 12 (7.8) | 9 (11) | 0.381 |
| Initiation modality | ||||
| At home | 181 (78) | 126 (82) | 55 (69) | 0.018 |
| In hospital | 52 (22) | 27 (18) | 25 (31) | 0.018 |
| Time from NIV requirement assessment to initiation (days) | 12.3±16.6 | 12.6±19.1 | 11.5±10.2 | 0.647 |
| Died before the 30th day | 12 (5) | 0 (0) | 12 (15) | |
| Neurological assessment | ||||
| ALSFRS-R score | 32.9±7.28 | 34.3±6.36 | 30.5±8.21 | 0.003 |
| Time from symptoms onset to NIV initiation (months) | 28.2±24.1 | 28.9±24.7 | 26.6±22.9 | 0.519 |
| Time from diagnosis to NIV initiation (months) | 14.9±18.6 | 15.3±18.2 | 14±19.5 | 0.623 |
| Bulbar symptoms at NIV initiation | 122 (52.6) | 75 (49) | 47 (59) | 0.173 |
| Gastrostomy in the follow-up | 13 (5.6) | 8 (5) | 5 (6) | 0.747 |
| Frontotemporal dementia | 18 (7.7) | 11 (7) | 7 (9) | 0.672 |
| Respiratory assessment | ||||
| FVC (L) | 2.33±0.871 | 2.4±0.842 | 2.17±0.921 | 0.108 |
| FVC (%) | 68.7±20.9 | 71.5±21.5 | 62.9±18.2 | 0.007 |
| Peak flow (L·s−1) | 4.58±1.99 | 4.8±2.04 | 4.08±1.81 | 0.036 |
| Peak flow (%) | 63.2±24.7 | 65.6±25.3 | 57.6±22.5 | 0.053 |
| MIP (cmH2O) | 44.7±23.7 | 46.6±22.8 | 40.2±25.6 | 0.178 |
| SNIP (cmH20) | 45.4±22.4 | 56±24.4 | 34.8±15.7 | 0.104 |
| SpO2 night-time <90% (%) | 17.1±21.3 | 17.8±20.6 | 15.8±22.6 | 0.531 |
| SpO2<90% more than 5% of night-time | 135 (68.2) | 95 (62) | 40 (50) | 0.024 |
| SpO2 minimum | 80.4±7.88 | 80.8±8.33 | 79.6±7.01 | 0.317 |
| SpO2 mean | 91.9±10.3 | 91.8±2.43 | 92.1±2.37 | 0.468 |
| ODI | 9.91±10.3 | 9.49±11.9 | 10.6±11.9 | 0.477 |
| PaCO2 (kPa) | 5.36±1 | 5.39±1.04 | 5.29±0.9 | 0.489 |
Data are presented as mean±sd or n (%) unless otherwise stated. ALSFRS-R: Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised; BMI: body mass index; FVC: forced vital capacity; MIP: maximal inspiratory pressure; ODI: oxygen desaturation index; PaCO2: arterial carbon dioxide tension; SNIP: sniff nasal inspiratory pressure; SpO2: oxygen saturation measured by pulse oximetry.