| Biomass group | Tobacco group | p-value | |
| Subjects n | 21 | 22 | |
| mMRC | 1.4±1.0 | 1.2±0.9 | 0.73 |
| SGRQ# | |||
| Symptoms | 46±28 | 30±18 | 0.03 |
| Activities | 58±20 | 46±19 | 0.02+ |
| Impact | 34±19 | 24±13 | 0.10+ |
| Total | 42±18 | 33±14 | 0.07 |
| Report of cough or sputum (from SGRQ) | |||
| Subjects n | 20 | 21 | |
| Cough n (%) | 18 (90) | 16 (76) | 0.23 |
| Sputum n (%) | 18 (90) | 15 (71) | 0.13 |
| Chronic Respiratory Questionnaire¶ | |||
| Dyspnoea | 17±10 | 14±8 | 0.19+ |
| Fatigue | 19±5 | 19±5 | 0.96 |
| Emotion | 35±8 | 39±8 | 0.58 |
| Control of disease (mastery) | 21±5 | 24±4 | 0.04+ |
| Total | 92±17 | 93±17 | 0.74 |
| Arterial blood gas | |||
| PaO2 mmHg | 49.3±7.7 | 52.5±4 | 0.11 |
| PaCO2 mmHg | 36.9±5.4 | 33.1±4 | 0.01 |
| pH | 7.41±0.03 | 7.42±0.04 | 0.33 |
| SaO2 % | 82±8 | 87±4 | 0.01 |
| 6MWD | |||
| SpO2 at rest % | 89±5 | 92±3 | 0.07 |
| SpO2 at end of walk test % | 80±9 | 84±4 | 0.04 |
| Distance m | 306±118 | 307±152 | 0.98 |
Data are presented as mean±sd, unless otherwise stated. mMRC: modified Medical Research Council dyspnoea scale; SGRQ: St George’s Respiratory Questionnaire; PaO2: arterial oxygen tension; PaCO2: arterial carbon dioxide tension; SaO2: arterial oxygen saturation; SpO2: arterial oxygen saturation measured by pulse oximetry. #: higher values represent worse health status; ¶: lower values represent worse health status; +: nonparametric test.