EVALUATION OF COLD-AIR CHALLENGE DATA IN A POPULATION-SAMPLE USING A MODEL OF BRONCHIAL HYPERREACTIVITY AND DISPOSITION TO BRONCHIAL OBSTRUCTION

To explore the role of bronchial hyperreactivity and obstruction after cold air challenge, data from a cross-sectional study of more than 7, 000 10-year-old children were used. Current knowledge of hyperreactivi ty is primarily based on pharmacological provocation tests with variab le prechallenge flow rates and their decrease relative to baseline. Us ing forced expiratory volume (FEV) in 1 sec values before and after co ld air challenge, however, it is possible to define a subsample of chi ldren with predominant hyperreactivity and a subsample with predominan t obstruction after challenge. The prevalence of respiratory symptoms and the diagnoses in the two subsamples were compared. The analysis sh owed that children with bronchial obstruction have nearly the same fre quency of respiratory symptoms as those with bronchial hyperreactivity . A combined model of bronchial obstruction and hyperreactivity was, t herefore, more predictive of symptoms than a model of hyperreactivity alone.