Because there is no “gold standard” for defining asthma for epidemiology, we have defined current asthma as bronchial hyperresponslveness (BHR) plus recent wheeze (in the 12 months prior to study). To describe the characteristics of groups categorized by these measurements, we studied two samples of children aged 7 to 12 yr: 210 from a population sample and 142 self-identified asthmatics. Bronchial responsiveness to histamine was measured by the rapid method, respiratory symptom history, and asthma medication use by self-administered questionnaire to parents and atopy by skin prick tests to 14 allergens. Children recorded daily Airflometer readings and symptom scores for 2 wk. Children with current asthma had more severe bronchial responsiveness, greater Airflometer variability, more symptoms, more atopy (particularly to house dust mites), and used more asthma medication than children with BHR or recent wheeze alone. Children with BHR, but not with recent wheeze, were intermediate between the current asthma and normal groups in terms of bronchial responsiveness, Airflometer variability, and atopy. Children with recent wheeze and normal responsiveness differed from the normal group only in symptoms and medication use. Our definition of current asthma discriminates a group of children that is clearly different in terms of both clinical features and physiologic measures. As such, it is the most useful definition to date for measuring the prevalence of clinically important asthma in populations.

We conducted all studies during June and July in primary schools in and around Belmont, a coastal suburb some 150 km north of Sydney, Australia. We invited all children in years 3, 4, and 5 (ages 8-11 years) at selected schools to participate and studied only children who had parental consent. Parents completed a questionnaire about symptoms, diagnosis, and treatment of asthma and other allergic illnesses. We used a histamine challenge test to measure airway hyperresponsiveness and assessed atopy by skin prick tests to house dust, Dermatophagoides farinae, D pterronyssinus, ryegrass, cockroach, cat, Alternaria tenuis (Hollistier-Stier, Spokane, WA, USA). Questionnaires and tests were the same as in 1992.1 The data collected in 1982 are not directly comparable because only 8-10 year old children were included and some equipment was different1. Owing to a low initial response rate in 2002 a single page anonymous questionnaire was issued to parents who had not consented to their child's participation in the clinical tests. The limited data from this questionnaire have been included.

A cross-sectional study finds that symptoms and spirometric evidence of chronic obstructive pulmonary disease are common among people aged 40 years or older in Australia, and increase with age.

To evaluate the association between growth in height and growth in lung function, and to identify the potential temporal relationships between airway hyperresponsiveness (AHR), respiratory symptoms, and lung function growth during adolescence and young adulthood, we analyzed data collected from the Belmont cohort. Among the 718 schoolchildren initially studied at 1982 (aged 8–10 yr), 557 were studied between two times and six times at 2-yr intervals until 1992. Baseline lung function, AHR by histamine inhalation test, and recent wheeze by questionnaires, were measured at each visit. We found that between 17 and 19 yr of age, when growth in height had stopped, growth in FEV1 was approximately 200 ml/yr in boys and 100 ml/yr in girls. Peak growth velocity of height occurred at age 13 both in boys and in girls, whereas peak growth velocity of FEV1 occurred at the same age only in girls and 1 yr later in boys. Having AHR and recent wheeze at the previous study time were both associated with lower subsequent growth in FEV1, but not with subsequent growth in FVC. We conclude that lung function continues to grow after the cessation of height growth and that growth in FEV1 is reduced in subjects with AHR and/or recent wheeze.

Background: Although many children with asthma may have a remission as they grow and other children who did not have asthma may develop asthma in adult life, knowledge about the factors that influence the onset and prognosis of asthma during adolescence and young adulthood is very limited. Methods: A cohort of 8–10 year old children (n=718) living in Belmont, New South Wales, Australia were surveyed six times at 2 yearly intervals from 1982 to 1992, and then again 5 years later in 1997. From this cohort, 498 subjects had between three and seven assessments and were included in the analysis. Atopy, airway hyperresponsiveness (AHR), and wheeze in the last 12 months were measured at each survey. Late onset, remission, and persistence were defined based on characteristics at the initial survey and the changes in characteristics at the follow up surveys. Results: The proportion of subjects with late onset atopy (13.7%) and wheeze (12.4%) was greater than the proportion with remission of atopy (3.2%) and wheeze (5.6%). Having atopy at age 8–12 years (OR 2.8, 95% CI 1.5 to 5.1) and having a parental history of asthma (OR 2.0, 95% CI 1.02 to 4.13) were significant risk factors for the onset of wheeze. Having AHR at age 8–12 years was a significant risk factor for the persistence of wheeze (OR 4.3, 95% CI 1.3 to 15.0). Female sex (OR 1.9, 95% CI 1.01 to 3.60) was a significant risk factor for late onset AHR whereas male sex (OR 1.9, 95% CI 1.1 to 2.8) was a significant risk factor for late onset atopy. Conclusions: The onset of AHR is uncommon during adolescence, but the risk of acquiring atopy and recent wheeze for the first time continues during this period. Atopy, particularly present at the age of 8–10 years, predicts the subsequent onset of wheeze.