Differences in rate of decline in pulmonary function indices before and after NIV initiation
| Pulmonary function indices | All phenotypes | ALS-bulbar | ALS-cervical | ALS-lumbar | Flail limb |
|---|---|---|---|---|---|
| FVC | |||||
| n | 206 | 58 | 53 | 75 | 19 |
| Slope difference (95% CI) L/year | 0.16 (0.04 to 0.29) | 0.36 (0.09 to 0.64) | −0.18 (−0.42 to 0.06) | 0.17 (−0.06 to 0.41) | 0.47 (0.24 to 0.70) |
| p Value | 0.009 | 0.009 | 0.141 | 0.159 | <0.001 |
| FEV1 | |||||
| n | 207 | 58 | 53 | 76 | 20 |
| Slope difference (95% CI) L/year | 0.12 (0.01 to 0.23) | 0.18 (−0.05 to 0.42) | −0.16 (−0.36 to 0.04) | 0.18 (−0.03 to 0.39) | 0.31 (0.10 to 0.51) |
| p Value | 0.029 | 0.140 | 0.128 | 0.094 | 0.003 |
| MEP | |||||
| n | 200 | 56 | 52 | 74 | 18 |
| Slope difference (95% CI) mm Hg per year | 9.14 (4.87 to 13.41) | 4.83 (−5.23 to 14.90) | 5.88 (−1.42 to 13.20) | 9.79 (2.46 to 17.12) | 15.78 (7.80 to 23.77) |
| p Value | <0.001 | 0.347 | 0.114 | 0.009 | <0.001 |
| MIP | |||||
| n | 196 | 53 | 51 | 74 | 18 |
| Slope difference (95% CI) mm Hg per year | 6.12 (2.54 to 9.88) | 0.81 (−5.15 to 6.77) | 13.19 (6.48 to 19.90) | 10.35 (2.60 to 18.09) | −1.78 (−9.05 to 5.48) |
| p Value | 0.001 | 0.790 | <0.001 | 0.009 | 0.630 |
| SNIP | |||||
| n | 166 | 48 | 43 | 60 | 15 |
| Slope difference (95% CI) mm Hg per year | 2.03 (−2.33 to 6.39) | 11.52 (3.20 to 19.84) | 5.04 (−2.98 to 13.07) | 1.85 (−6.23 to 9.93) | −1.34 (−9.39 to 6.71) |
| p Value | 0.362 | 0.007 | 0.218 | 0.654 | 0.744 |
ALS, amyotrophic lateral sclerosis; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; MEP, maximal expiratory pressures; MIP, maximal inspiratory pressure; NIV, non-invasive ventilation; SNIP, sniff nasal inspiratory pressure.