Characteristics of the idiopathic pulmonary fibrosis (IPF) patient population and the control group
| IPF group | Control group | |
| Demographic characteristics | ||
| Number of cases | 41 | 41 |
| Sex male/female | 15/26 | 15/26 |
| Age yrs | 63.5 (38–80) | 64.0 (45–83) |
| Smoking yes/no/missing | 4/35/6 | |
| Medical characteristics | ||
| Oxygen use yes/no/missing | 14/27 | |
| If yes now often? 24 h a day/sometimes | 6/8 | |
| Steroid use at time of study yes/no | 28/13 | |
| Time since diagnosis yrs | 5.8±5.4 | |
| FEV1 % pred | 70.1±21.5 | |
| TL, CO % pred | 45.3±14.9 | |
| PO2 at rest kPa | 9.1±1.7 | |
| PO2 during exercise kPa | 7.0±1.2 | |
| PO2 difference score kPa | 2.7±1.5 | |
| Symptoms | ||
| Cough yes/no | 35/6 | |
| Reduced exercise capacity yes/no | 34/7 | |
| Severity of dyspnoea possible range 0–7 | 3.8±2.0 | |
| Psychological characteristics | ||
| BDI-scores | 11.9±6.0 | |
| CDI-scores | 7.0±5.1 |
Data are expressed in means, (range) or as mean±SD
FEV1 forced expiration volume in one second
TL,CO transfer factor of the lung for carbon monoxide
PO2: arterial oxygen tension
BDI: Beck Depression Inventory
CDI: Cognitive Depression Index