Respiratory symptoms suggestive of asthma at baseline (prevalent) and during follow-up (incidence) according to incidence of probable occupational asthma and atopic status
| Probable occupational asthma | |||
| Present | Absent | ||
| Atopic | Non-atopic | ||
| Subjects (n) | 24 | 6 | 367 |
| Symptoms suggestive of asthma# | |||
| At baseline | 9 (37.5) | 0 | 59 (16.1) |
| Incident¶ | 8/15 (53.3) | 1/6 (16.7) | 51/308 (16.6) |
| Exercise-induced symptoms | |||
| At baseline | 11 (45.8) | 0 | 70 (19.1) |
| Incident¶ | 6/13 (46.2) | 1/6 (16.7) | 50/297 (16.8) |
| Symptoms on exposure to cold air | |||
| At baseline | 5 (20.8) | 0 | 53 (14.4) |
| Incident¶ | 9/19 (47.4) | 1/6 (16.7) | 28/314 (8.9) |
Data are presented as n (%)
#: at least two of the following symptoms: wheezing, chest tightness, dyspnea, awakening at night with cough
¶: the denominator is the number of subjects without symptoms at baseline