Table 1.
 Admission diagnoses of 180 controls*
| Diagnosis | No (%) of controls (n=180)) |
|---|---|
| Elective ear, nose, or throat surgery | 73 (41) |
| Asthma | 51 (28) |
| Obstructive sleep apnoea | 22 (12) |
| Chronic obstructive pulmonary disease | 16 (9) |
| Gastro-oesophageal reflux | 11 (6) |
| Tuberculosis | 11 (6) |
| HIV/AIDS | 10 (6) |
| Arterial hypertension | 8 (4) |
| Interstitial pneumopathy | 7 (4) |
| Diabetes | 6 (3) |
| Lung cancer | 5 (3) |
| Chronic haemoptysis | 5 (3) |
| Chronic heart disease | 4 (2) |
| Pleural disease | 4 (2) |
| Obesity | 4 (2) |
| Bronchiectasis | 3 (2) |
| Systemic autoimmune disease | 3 (2) |
| Thoracic surgery | 3 (2) |
| Pulmonary arterial hypertension | 3 (2) |
| Pneumocystis jirovecii pneumonia | 3 (2) |
| Congenital thoracic deformity | 2 (1) |
| Tracheal stenosis | 2 (1) |
| Chronic renal insufficiency | 2 (1) |
| Pulmonary nodule | 2 (1) |
| Pulmonary sequestration | 1 (0.6) |
| Elective tracheostomy | 1 (0.6) |
| Pulmonary embolism | 1 (0.6) |
| Bronchiolitis | 1 (0.6) |
| Hepatic cirrhosis | 1 (0.6) |
| Dermatitis | 1 (0.6) |
| Tobacco addiction | 3 (2) |
| Pregnancy | 1 (0.6) |
*Four patients had four diagnoses, 13 had three, 52 had two, and the remainder (n=111) had one.