Population characteristics
| Patient characteristics at initiation | Total | At-home patients | Inpatients | p-value |
| Anthropometric data | ||||
| Patients, n | 265 | 184 | 81 | |
| Age (years) | 68±11 | 68±11 | 69±9 | 0.577 |
| Male | 157 (63) | 114 (62) | 43 (65) | 0.645 |
| BMI (kg·m−2) | 24±4 | 24±4 | 23±4 | 0.141 |
| Smoking greater than 20 pack-years | 23 (9) | 16 (9) | 7 (11) | 0.684 |
| Neurological assessment | ||||
| ALSFRS-R score | 33±7 | 33±7 | 33±7 | 0.854 |
| Time from symptoms onset to NIV initiation (months) | 29±25 | 29±24 | 27±26 | 0.521 |
| Time from diagnosis to NIV initiation (months) | 15±18 | 17±20 | 10±13 | 0.016 |
| Bulbar symptoms at NIV initiation | 131 (53) | 94 (51) | 37 (56) | 0.513 |
| Gastrostomy in the follow-up | 13 (5) | 9 (5) | 4 (6) | 0.714 |
| Frontotemporal dementia | 19 (8) | 15 (8) | 4 (6) | 0.582 |
| Respiratory assessment | ||||
| FVC (L) | 2.32±0.89 | 2.40±0.84 | 2.07±0.10 | 0.042 |
| FVC (%) | 68.9±20.9 | 71.60±19.97 | 59.4±21.7 | <0.001 |
| Peak flow (L·s−1) | 4.59±2.02 | 4.75±1.98 | 4.01±2.10 | 0.066 |
| Peak flow (%) | 63.4±24.8 | 65.65±24.65 | 54.8±23.7 | 0.017 |
| MIP (cmH2O) | 44.4±23.9 | 44.26±23.96 | 45.1±24 | 0.877 |
| SNIP (cmH20) | 45.9±20.8 | 47.88±23.89 | 43.2±17.5 | 0.692 |
| SpO2 night-time <90% (%) | 17±21.4 | 15.16±18.59 | 23.2±28.1 | 0.023 |
| SpO2<90% more than 5% of night-time | 142 (68) | 114 (62) | 28 (58) | 0.118 |
| SpO2 minimum | 80.4±7.85 | 80.7±7.77 | 79.4±8.12 | 0.345 |
| SpO2 mean | 91.9±2.36 | 92.1±1.98 | 91.3±3.29 | 0.070 |
| ODI | 9.63±10.1 | 9.25±8.92 | 10.9±13.4 | 0.357 |
| PaCO2 (kPa) | 5.39±1.04 | 5.07±0.58 | 6.21±1.44 | <0.001 |
| NIV initiation criteria | ||||
| Clinical signs + | ||||
| PaCO2>6.1 kPa | 34 (13) | 0 | 34 (42) | |
| FVC <80% only | 84 (32) | 65 (35) | 19 (24) | 0.056 |
| SpO2<90%, time >5% only | 74 (28) | 72 (39) | 2 (2) | <0.001 |
| Both FVC <80% and SpO2<90%, time >5% | 42 (16) | 42 (23) | 0 (0) | <0.001 |
| SNIP <60 cmH2O | 1 (0) | 1 (1) | 0 (0) | 0.506 |
| Other | 30 (11) | 4 (2) | 26 (32) | <0.001 |
| Time from NIV requirement assessment to initiation (days) | 12.5±16.5 | 8.72±6.47 | 29±31.1 | <0.001 |
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; NIV: noninvasive ventilation; PaCO2: arterial carbon dioxide tension; SNIP: sniff nasal inspiratory pressure; SpO2: oxygen saturation measured by pulse oximetry.