Table 2

Incidence of respiratory symptoms and change in lung function tests between the initial and final phases in hairdressing and office apprentices

Hairdressing apprenticesOffice apprenticesp 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.
    Morning cough (%)
    Cough day/night (%)
    Morning sputum (%)
    Wheezing (%)
    Dyspnoea with wheezing (%)
    MHR* (%)
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) (%)21.614.90.36
Change in methacholine slope,‡ mean (SD)0.044 (0.19)−0.025 (0.26)0.04