Incidence, risk factors and re‐exacerbation rate of severe asthma exacerbations in a multinational, multidatabase pediatric cohort study

BACKGROUND: There are sparse real‐world data on severe asthma exacerbations (SAE) in children. This multinational cohort study assessed the incidence of and risk factors for SAE and the incidence of asthma‐related rehospitalization in children with asthma. METHODS: Asthma patients 5‐17 years old with ≥1 year of follow‐up were identified in six European electronic databases from the Netherlands, Italy, the UK, Denmark and Spain in 2008‐2013. Asthma was defined as ≥1 asthma‐specific disease code within 3 months of prescriptions/dispensing of asthma medication. Severe asthma was defined as high‐dosed inhaled corticosteroids plus a second controller. SAE was defined by systemic corticosteroids, emergency department visit and/or hospitalization all for reason of asthma. Risk factors for SAE were estimated by Poisson regression analyses. RESULTS: The cohort consisted of 212 060 paediatric asthma patients contributing to 678 625 patient‐years (PY). SAE rates ranged between 17 and 198/1000 PY and were higher in severe asthma and highest in severe asthma patients with a history of exacerbations. Prior SAE (incidence rate ratio 3‐45) and younger age increased the SAE risk in all countries, whereas obesity, atopy and GERD were a risk factor in some but not all countries. Rehospitalization rates were up to 79% within 1 year. CONCLUSIONS: In a real‐world setting, SAE rates were highest in children with severe asthma with a history of exacerbations. Many severe asthma patients were rehospitalized within 1 year. Asthma management focusing on prevention of SAE is important to reduce the burden of asthma.