*: frequency per year of hospitalization in a hospital Emergency Department (ED) for severe asthmatic exacerbation, calculated since two years of age
#: an obstructive defect is defined by a z-score of FEV1/FVC < -1.645.
BMI denotes body mass index, SABA denotes short-acting beta agonist treatment, ICS denotes inhaled corticosteroid, BED denotes beclomethasone-equivalent daily dose, LABA denotes long-acting beta agonist
$: severe exacerbation is defined according to Reddel et al.26
ยง: Severe asthma defined by FEV1< 80% predicted and a z-score of FEV1/FVC < -1.645, according to international recommendations23