Real life data on incidence and risk factors of severe asthma exacerbations in children in primary care.

Real-life data on the incidence rates (IR) and risk factors of severe asthma exacerbations in children are sparse. We aimed to assess IR and risk factors of severe asthma exacerbations in children in real life. We conducted a population-based cohort study using a Dutch GP database containing complete medical records of >1 million patients. All records of children with physician-diagnosed asthma aged 5-18 years between 2000 and 2012 were examined for exacerbations, defined as either hospitalization, emergency department visit or need of systemic steroids for asthma. IR was expressed as number of exacerbations per person year (PY). We identified 14,303 asthmatic children with 35,118 PY of follow-up and 732 exacerbations. The overall IR was 2.1/100PY (95% CI 1.9-2.2), 4.1/100PY (3.8-4.4) for children on asthma treatment. Re-exacerbation occurred in 2% (1.3-4.3) of patients within 1 month, in 25% (20.6-28.8) within 1 year. Predictors for (frequent) exacerbations were age, medication use and prior exacerbations (all p < 0.001). The overall IR of severe asthma exacerbations was 4/100PY in children on asthma treatment, highest in spring and fall. 25% of the patients with an exacerbation will experience a next exacerbation within 1 year. More severe asthma is a predictor of subsequent and future exacerbations.