Table 1.
Comparison of baseline characteristics in cases and controls
| Variable | NPPV (n=15) | Controls (n=12) |
|---|---|---|
| Age (years)† | 70 (66–73) | 68 (65–78) |
| Sex (% male) | 8 (53) | 12 (100)* |
| BMI (kg/m2) | 24.8 (2.8) | 24.8 (4.8) |
| Pack-years of smoking | 59 (29) | 61 (30) |
| FEV1 %pred | 30.3 (7) | 29.6 (7.4) |
| FVC %pred | 68.8 (14.1) | 59.4 (8) |
| NIF (cm H2O) | −48.9 (14.5) | −63.2 (23.9) |
| PaCO2 (mmHg) | 42.4 (5.6) | 41.9 (4.6) |
| PaO2 (mmHg) | 65.1 (13.3) | 73.9 (9.9) |
| 6MWD (m) | 284 (101) | 321 (91) |
| CRQ score | ||
| Dyspnea | 3.8 (1) | 3.7 (1) |
| Fatigue | 4.3 (1) | 4.1 (1) |
| Emotional function | 5.5 (0.7) | 5.3 (1.1) |
| Mastery | 5 (1.1) | 5.3 (1.4) |
| Dyspnea | ||
| TDI-Function | 1.9 (0.7) | 1.5 (0.7) |
| TDI-Task | 1.3 (0.5) | 1.4 (0.7) |
| TDI-Effort | 1.3 (0.5) | 1.3 (0.5) |
| TDI total | 4.5 (1.6) | 4.2 (1.5) |
| PSQI | 3.7 (3) | 6.1 (3.2) |
Notes: All results are expressed as the mean (standard deviation) except for †median (interquartile range).
*
P<0.05.
Abbreviations: FEV1, forced expiratory volume in the first second; %pred, percent predicted; FVC, forced vital capacity; NIF, negative inspiratory force; NPPV, noninvasive positive pressure ventilation; PaCO2, partial pressure of carbon dioxide in arterial blood; PaO2, partial pressure of oxygen in arterial blood; 6MWD, six-minute walk distance; CRQ, Chronic Respiratory Disease Questionnaire; TDI, Transitional Dyspnea Index at baseline; PSQI, Pittsburgh Sleep Quality Index; BMI, body mass index.