Basic and clinical characteristics at recruitment between 1995 and 1999, comparing subjects in remission and subjects with persistent asthma at follow-up
| All | Persistent asthma | Remission | p-value | |
| Subjects n | 205 | 182 | 23 | |
| Female sex | 134 (65.4) | 121 (66.5) | 13 (56.5) | 0.344 |
| Age at asthma onset | 39.3±10.3 | 39.4±10.2 | 38.6±11.6 | 0.718 |
| BMI | 25.9±4.5 | 25.9±4.4 | 26.7±4.7 | 0.386 |
| Family history of asthma | 83 (40.5) | 77 (42.3) | 6 (26.1) | 0.135 |
| BMI classification | ||||
| Normal weight | 95 (46.3) | 85 (46.7) | 10 (43.5) | |
| Overweight | 79 (38.5) | 70 (38.5) | 9 (39.1) | |
| Obesity | 31 (15.1) | 27 (14.8) | 4 (17.4) | 0.717+ |
| Smoking habits | ||||
| Nonsmoker | 105 (51.2) | 95 (52.2) | 10 (43.5) | |
| Ex-smoker | 64 (31.2) | 57 (31.3) | 7 (30.4) | |
| Current smoker | 36 (17.6) | 30 (16.5) | 6 (26.1) | 0.276+ |
| Occupational exposure to gas, dust or fumes | 66 (33.3) | 61 (34.9) | 5 (21.7) | 0.210 |
| Educational level | ||||
| Primary school | 21 (10.5) | 20 (11.3) | 1 (4.3) | |
| High school | 92 (46.0) | 81 (45.8) | 11 (47.8) | |
| Higher education | 87 (43.5) | 76 (42.9) | 11 (47.8) | 0.417+ |
| Lung function | ||||
| FEV1 % predicted | 89.0±13.4 | 88.3±13.7 | 94.6±10.1 | 0.034 |
| FVC % predicted | 87.1±11.6 | 86.5±11.7 | 92.0±9.5 | 0.034 |
| Bronchial hyperreactivity PC20# | ||||
| PC20 ≤1 mg·mL−1 | 89 (48.1) | 83 (50.9) | 6 (27.3) | 0.037 |
| PC20 ≤2 mg·mL−1 | 120 (64.9) | 109 (66.9) | 11 (50.0) | 0.120 |
| Atopic comorbidities | ||||
| Hay fever | 82 (40.0) | 73 (40.1) | 9 (39.1) | 0.928 |
| Eczema | 68 (33.2) | 62 (34.1) | 6 (26.1) | 0.444 |
| Nasal polyps | 21 (10.2) | 20 (11.0) | 1 (4.3) | 0.285 |
| Positive skin-prick test¶ | 85 (42.1) | 75 (41.9) | 10 (43.5) | 0.885 |
Data are presented as n (%) or mean±sd, unless otherwise stated. BMI: body mass index; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PC20: provocative concentration causing a 20% fall in FEV1. #: among the 185 participating in metacholine challenge test at recruitment; ¶: among the 202 participating in skin-prick test; +: analysis performed in a 3×2 table. Bold values indicate p<0.05.