Clinical characteristics of patients with or without asthma (n=33 815)
| Patient characteristics | Asthmatic patients | Non-asthmatic patients | p-value |
| Subjects n | 4276 | 29 539 | |
| Age years, mean±sd | 42.2±13.7 | 43.8±14.2 | <0.001 |
| Age 46 to ≤65 years | 1394 (32.6) | 10 729 (36.3) | |
| BMI kg m−2, median (IQR), n=33 347 | 25.3 (22.3–29.4) | 24.8 (22.0–28.3) | <0.001 |
| Female sex, n=33 774 | 2989 (70.0) | 18 312 (62.1) | <0.001 |
| Comorbid conditions | |||
| Overweight (BMI 25–30 kg m−2), n=33 347 | 1210 (28.6) | 8704 (29.9) | <0.001 |
| Obesity (BMI >30 kg m−2), n=33 347 | 979 (23.1) | 5124 (17.6) | |
| Hypertension | 541 (12.7) | 3591 (12.2) | 0.369 |
| Diabetes | 193 (4.5) | 1494 (5.1) | 0.136 |
| Heart failure | 102 (2.4) | 551 (1.9) | 0.024 |
| COPD | 217 (5.1) | 378 (1.3) | <0.001 |
| Coronary artery disease | 72 (1.7) | 393 (1.3) | 0.074 |
| Cancer under treatment | 34 (0.8) | 355 (1.2) | 0.024 |
| Chronic renal disease | 61 (1.4) | 325 (1.1) | 0.072 |
| Respiratory symptoms | |||
| Cough | 2916 (68.2) | 18 120 (61.3) | <0.001 |
| Shortness of breath | 2898 (67.8) | 13 205 (44.7) | <0.001 |
| Chest pain | 1371 (32.1) | 7043 (23.8) | <0.001 |
| Chest tightness | 1491 (34.9) | 7215 (24.4) | <0.001 |
| General symptoms | |||
| Fatigue | 3758 (87.9) | 25 368 (85.9) | <0.001 |
| Fever | 2062 (48.2) | 14 405 (48.8) | 0.517 |
| Shivers | 2439 (57.0) | 15 808 (53.5) | <0.001 |
| Myalgia | 2505 (58.6) | 15 932 (53.9) | <0.001 |
| Gastrointestinal symptoms | |||
| Anorexia | 1695 (39.6) | 11 387 (38.5) | 0.176 |
| Nausea/vomiting | 1210 (28.3) | 6838 (23.1) | <0.001 |
| Diarrhoea | 1655 (38.7) | 10 175 (34.4) | <0.001 |
| Neurological symptoms | |||
| Anosmia | 1300 (30.4) | 9924 (33.6) | <0.001 |
| Ageusia | 1326 (31.0) | 9700 (32.8) | 0.018 |
| Cutaneous symptoms | |||
| Rash | 507 (11.9) | 2614 (8.8) | <0.001 |
| Chilblains | 88 (2.1) | 530 (1.8) | 0.253 |
| Conjunctivitis | 392 (9.2) | 2021 (6.8) | <0.001 |
Qualitative data are expressed as frequency (% of total). In case of variable with missing data, the number of patients with available information is specified. BMI: body mass index; IQR: interquartile range presented as first quartile (Q1)–third quartile (Q3); sd: standard deviation.