Comorbidities
| Severe nonsmoking asthma | Smokers and ex-smokers with severe asthma | Mild/moderate nonsmoking asthma | Healthy nonsmoking controls | p-value | p-value# | |
| Subjects n | 311 | 110 | 88 | 101 | ||
| Allergic rhinitis diagnosed | 164/277 (59.2%) | 44/101 (43.6%) | 42/70 (60%) | 5/30 (16.7%) | <0.001 | 0.442 |
| Hayfever diagnosed | 135/284 (47.5%) | 51/100 (51%) | 46/73 (63.0%) | 10/33 (30.3%) | 0.019 | 0.024 |
| Nonallergic rhinitis diagnosed | 42/284 (14.8%) | 17/101 (16.8%) | 8/72 (11.1%) | 1/34 (2.9%) | 0.090 | 0.356 |
| Nasal polyps diagnosed | 103/291 (35.4%) | 34/101 (33.7%) | 7/76 (9.2%) | 3/34 (8.8%) | <0.001 | <0.001 |
| Eczema diagnosed | 107/294 (36.4%) | 31/101 (30.7%) | 25/75 (33.3%) | 5/35 (14.3%) | 0.013 | 0.789 |
| GORD diagnosed | 135/289 (46.7%) | 63/99 (63.6%) | 16/75 (21.3%) | 4/35 (11.4%) | <0.001 | <0.001 |
GORD: gastro-oesophageal reflux disease. #: severe asthma (nonsmoking asthma group and smokers and ex-smokers with severe asthma group combined) versus mild/moderate nonsmoking asthma group.