Better asthma control in preschoolers may mean better long-term outcomes
Published: January 17, 2022
More than half of children with persistent asthma begin their disease course before they reach three years of age. Moreover, preschoolers experience a 2-to-3 fold higher rate of visits to the emergency department for asthma than other age groups, suggesting that preschool could represent a vulnerable period during which repeated exacerbations may increase susceptibility toward a more severe disease trajectory. However, whether asthma control following a diagnosis in preschool is associated with long-term adverse outcomes remains unclear.
According to a recently published article in The Journal of Allergy and Clinical Immunology: In Practice, asthma control trajectories shortly after a diagnosis in preschool appear to play a very important role in long-term unsatisfactory asthma control and morbidity. In a large multi-center population-based retrospective cohort study, Longo et al. used Canadian administrative health and drug data from 4 provinces to measure asthma control trajectories over the course of two years post-diagnosis in 50188 preschoolers and then followed them long-term until their 16th birthday, date of asthma remission, or lost-to-follow-up, whichever occurred first. The asthma control trajectories were measured using a validated index over four 6-month periods post-diagnosis and were classified into: controlled throughout, improving control, fluctuating control, worsening control, and out-of-control throughout.
The primary outcome, long-term unsatisfactory control, was defined as ≥4 short-acting beta-2 agonist average doses per week or an exacerbation, measured within 6 months before follow-up ages 6, 8, 10, 12, 14, and 16 years. The secondary outcome, health care utilization, was defined as the number of medical visits for asthma in the 24 months prior to each follow-up age. The strength of the relationships between asthma control trajectories post-diagnosis and the primary and secondary outcomes were estimated using robust Poisson regression and negative binomial models, respectively, in each province. Province-specific estimates were then summarized using a random effects model.
The study found that, when compared to children who were controlled throughout the 2 years shortly following a diagnosis in preschool, the average risks of long-term unsatisfactory control were 38%, 54%, 70% and 100% higher for children whose trajectories were improving, fluctuating, worsening, and out-of-control throughout, respectively. Similarly, incrementally higher rates of long-term health care utilization for asthma were observed for each suboptimal trajectory, with 25%, 45%, 54%, and 89% higher rates for the improving control, fluctuating control, worsening control, and out-of-control throughout trajectories.
These results suggest that optimizing control in preschool could potentially improve disease evolution, shifting from treatment to prevention of exacerbations in preschoolers diagnosed with asthma.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.