Incidence of respiratory symptoms and change in lung function tests between the initial and final phases in hairdressing and office apprentices
| Hairdressing apprentices | Office apprentices | p value | |
|---|---|---|---|
| *MHR: mucosal hyperresponsiveness, defined in this study as the presence of one or more of the following symptoms: fit of coughing, sneezing or runny nose, eye symptoms, and acute dyspnoea. | |||
| †Δ: % predicted at the final phase − % predicted at the initial phase. | |||
| ‡Methacholine dose-response slope, defined by the percent decline in FEV1 divided by the final cumulative dose of methacholine administered. Change in methacholine slope defined as log(slope+0.02) at the final phase – log(slope+0.02) at the initial phase. | |||
| Symptoms | (n=191) | (n=189) | |
| Morning cough (%) | 2.7 | 3.3 | 0.71 |
| Cough day/night (%) | 4.3 | 4.7 | 0.84 |
| Morning sputum (%) | 1.6 | 1.1 | 0.68 |
| Wheezing (%) | 10.0 | 11.5 | 0.66 |
| Dyspnoea with wheezing (%) | 3.9 | 6.6 | 0.26 |
| MHR* (%) | 26.2 | 26.1 | 0.99 |
| Lung function tests | (n=119) | (n=76) | |
| ΔFVC, mean (SD)† | −1.0 (7.4) | 0.8 (7.4) | 0.09 |
| ΔFEV1, mean (SD) | −2.5 (8.4) | 0.0 (7.4) | 0.03 |
| ΔFEV1/FVC, mean (SD) | −1.3 (4.1) | −0.6 (3.7) | 0.29 |
| ΔFEF25–75%, mean (SD) | −4.8 (14.6) | −0.2 (15.9) | 0.04 |
| Methacholine challenge | |||
| BHR (15% decrease in FEV1) (%) | 21.6 | 14.9 | 0.36 |
| Change in methacholine slope,‡ mean (SD) | 0.044 (0.19) | −0.025 (0.26) | 0.04 |