PURPOSE OF THE STUDY.
The goal of this study was to evaluate whether seasonal variations in asthma (with the highest incidence in September) can be documented in a large cohort of children in primary care and to determine the impact of age, gender, and urban/rural living.
A historical population of children aged 2 to 15 years in Israel’s Clalit Health Services registry, seen from 2005 to 2009, were included in this study. A total of 919 873 children were identified.
Electronic record reviews were conducted. The key study outcomes were the diagnosis of asthma exacerbations and asthma medication prescriptions, analyzed according to week of diagnosis. Statistical models were built to assess relative strength of secular trends, seasonality, and age group.
The authors documented that 8.9% of children were asthmatic, and 62% were boys. The age groups were as follows: 49% aged 2 to 5 years, 24% aged 6 to 9 years, and 27% aged 10 to16 years. There was a 2.01-fold increase in pediatric asthma exacerbations and a 2.28-fold increase in prescriptions of asthma bronchodilator medications during September compared with August. The association between the opening of school and the incidence of asthma-related visits to the primary care physician was greatest in children aged 2 to 5 years (odds ratio: 2.15) and 6 to 11 years (1.90-fold). Adolescents had a lesser peak (1.81-fold). There was a second rise in late fall, with fluctuations throughout winter, and a trough in summer.
There is an enhanced risk of asthma exacerbations and unscheduled visits to primary care physicians strongly related to return to school after summer vacations.
This study is the largest epidemiologic trial to date demonstrating a well-recognized peak in asthma exacerbations after the return to school, particularly in September; this peak is likely related to viral illness, environmental allergens, and/or lack of controller medications. Prophylaxis, particularly with inhaled steroid controller medication beginning at the end of August, is recommended by the authors, particularly for children with multifactorial asthma.
- Copyright © 2014 by the American Academy of Pediatrics