Characteristics of 27 treated and 15 control chronic obstructive pulmonary disease patients
| NIMV | s-NIMV | p-value | |
| Age yr | 66±9 | 69±7 | 0.25 |
| Sex female/male | 4/23 | 2/13 | 0.89 |
| BMI kg·m−2 | 23±4 | 23±4 | 0.88 |
| Smoking history pack-yrs | 67±28 | 58±16 | 0.17 |
| SABD as needed n | 27 | 15 | 1.00 |
| SABD q.i.d. n | 20 | 10 | 0.61 |
| LABD n | 17 | 10 | 0.85 |
| ICS n | 15 | 9 | 0.78 |
| THEO n | 23 | 14 | 0.44 |
| FEV1 % pred | 30±8 | 35±9 | 0.14 |
| FVC % pred | 73±14 | 79±17 | 0.20 |
| 6MWD m | 329±103 | 380±94 | 0.12 |
| BDI points | 3.5±1 | 3.3±1 | 0.45 |
Values are expressed as mean±sd unless otherwise stated. NIMV: noninvasive mechanical ventilation; s-NIMV: sham-NIMV; BMI: body mass index; SABD: short-acting bronchodilator; LABD: long-acting bronchodilator; ICS: inhaled corticosteroid; THEO: theophylline; FEV1: forced expiratory volume in one second; FVC: forced vital capacity; 6MWD: 6-min walking distance; BDI: baseline dyspnoea index.