Comparison of general respiratory symptoms in swimming pool employees and general respiratory symptoms in the general Dutch population, ELON(n = 2711), adjusted for age, smoking and sex
| General respiratory symptoms | Adjusted |
| Problems with breathing | 2.2 (1.8–2.8)* |
| Yes, constantly | 3.4 (1.9–5.9)* |
| Frequently, but it always improves | 1.3 (1.0–1.7) |
| Very rarely | 2.2 (1.7–2.7)* |
| Cough during last 12 months | 1.3 (1.0–1.7) |
| Phlegm during last 12 months | 1.8 (1.3–2.4)* |
| Tightness of chest during last 12 months | 1.4 (>1.0–1.8)* |
| Dyspnoea when walking on a flat surface with people of the same age | 7.2 (5.2–9.9)* |
| Wheeze during last 12 months | 0.8 (0.6–0.97) |
| Wheeze and shortness of breath during last 12 months | 0.9 (0.7–1.2) |
| Have you ever had asthma? | 2.4 (1.8–3.3)* |
| Was it doctor diagnosed? | 2.1 (1.5–3.0)* |
| Asthma attack during last 12 months | 2.6 (1.5–4.6)* |
| Woken up by shortness of breath during last 12 months | 1.5 (1.1–2.1)* |
| Shortness of breath after exercise during last 12 months | 1.0 (0.7–1.3) |
| Asthma medication during last 12 months | 3.6 (2.4–5.3)* |
Data are presented as odds ratio (95% confidence interval). *: p<0.05.