Asthma Exacerbations Peak After Start of School Year

Susan London

March 10, 2014

Children with asthma are most likely to have exacerbations shortly after returning to school in the fall, new data suggest, warranting consideration of prophylaxis starting at the end of summer for some.

A team led by Herman Avner Cohen, MD, from the Pediatric Ambulatory Community Clinic, Petach Tikva, Israel, and Sackler Faculty of Medicine, Tel Aviv University, Israel, conducted a retrospective population-based study among 82,234 asthmatic children aged 2 to 15 years.

Study results, published online March 10 in Pediatrics, showed a temporal pattern whereby primary care visits for exacerbations peaked in early fall, shortly after returning to school.

"Our study shows that returning to school after the summer vacation is strongly associated with an increased risk for a child experiencing an asthma exacerbation requiring medical attention. We propose that prophylactic treatment of asthma starting at the end of August should be considered in certain asthmatic children," the researchers write.

"Increasing adherence to prescribed inhaled asthma controller medication before and during the September school return period could be of benefit during this high-risk period, at least in the subgroup of children who have multifactorial asthma, and thus it may be effective in reducing morbidity," they add.

The study is noteworthy in that it is the largest of its kind to look at the seasonality of asthma exacerbations in a community setting, the researchers write. Thus, it captures all children with asthma (not just those sick enough to be referred to specialists) and has relevance for primary care providers.

Using the database from Israel's largest health fund, the research team identified 919,873 children aged 2 to 15 years in primary care between 2005 and 2009. Of those, 8.9% had physician-diagnosed asthma or wheezing.

Overall, 38% of these asthmatic children had at least 1 unscheduled primary care visit with a diagnosis of acute asthma, indicating an exacerbation.

The number of visits for exacerbations per 1000 health fund members showed an annual peak starting in the 37th to 38th week of the calendar year, corresponding to the first and second weeks after starting school in September. The number of visits rose again in mid-November. The rate remained high thereafter and fluctuated until spring (roughly week 12 of the next year). It was lowest in summer.

Specifically, going from August and early September (calendar weeks 34 - 36) to mid-September (calendar weeks 37 - 39), children had a 2.01-fold increase in the fraction of all visits that were made for asthma exacerbations. The number of prescriptions filled each week for a variety of asthma medications also increased (2.28-fold for bronchodilators, 2.04-fold for inhaled corticosteroids, 1.46-fold for leukotriene receptor antagonists, and 1.53-fold for combination therapies).

The effect of season on visits for exacerbations was less evident among children seen in clinics serving mainly the ultraorthodox Jewish population (explaining 36% of variance) than among children seen in clinics serving mainly the Arab population (explaining 69%) or the general Jewish population (explaining 58%). However, season had a similarly strong influence in urban and rural areas.

The authors have disclosed no relevant financial relationships.

Pediatrics. Published online March 10, 2014. Abstract


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