Current data collected in early adulthood
At the follow-up visit in 2010, when the participants were aged 17–20
years, they completed a questionnaire, which included questions about
asthma and allergy symptoms, asthma and allergy diagnoses, medication
and current smoking.17 In addition, all the
participants performed daily peak expiratory flow (PEF) measurements at
home for two weeks before the study visit. The criteria for abnormal PEF
were daily variability in PEF ≥ 20% or a bronchodilator response ≥ 15%
at least twice during this two week period.22 A
physician interviewed and examined all the participants and checked the
questionnaire and confirmed the responses with the
participants.17
Current asthma was defined as the presence of a previous asthma
diagnosis, together with symptoms suggestive of asthma during the last
12 months. These symptoms included recurrent wheezing, a prolonged
cough, a chronic night cough or continuous use of inhaled
corticosteroids.17 In addition, participants who
presented with abnormal home PEF monitoring results and reported
asthma-presumptive symptoms and/or repeated use of bronchodilators were
considered to have current asthma.17 Current asthma
was present in 26 (53%) of the 49 participants who attended the
follow-up visit in 2010 (Fig S1).
During the follow-up visit, SPTs for the following allergens were
performed: dog, cat, horse and cow dander; birch, common alder, Timothy
grass and mugwort pollens; and three types of common dust
mites.17 The presence of a positive SPT result for at
least one allergen was defined as current atopic sensitization. Current
allergy was defined as the presence of atopic sensitization and either
atopic dermatitis, allergic conjunctivitis or allergic rhinitis.