Asthma control in preschoolers: a strong predictor of long-term morbidity

Background: Irreversible lung function deficits have been observed by age 6 in children with preschool asthma, suggesting the possibility of long-term adverse outcomes. We examined the impact of asthma control shortly after diagnosis in preschool children on long-term control. Methods: We constructed Canadian birth cohorts from 4 provincial administrative databases. Preschool asthma was defined as 1 hospitalization or 2 physician visits for asthma within 2 years in children Results: Of the 118365 preschoolers with asthma, 50188 (42.4%) were included. Compared to children controlled throughout the 2 years post-diagnosis, suboptimal control was associated with a higher pooled RR for long-term poor control in a dose-response manner towards worse control patterns. Conclusions: Suboptimal control after diagnosis in preschool is a strong predictor of long-term poor control, suggesting a window of opportunity to improve future morbidity.