Incidence and risk factors of frequent asthma exacerbations in a multinational, multidatabase cohort study

Background: There is sparse real world evidence on the incidence and risk factors of frequent exacerbations in asthmatic patients. Aim: To assess incidence and risk factors of frequent exacerbations in asthmatic patients. Methods: Asthma patients aged ≥18 yrs with ≥1 year of follow-up were identified through the EU-ADR alliance in primary care databases from the Netherlands (IPCI), Italy (HSD), UK (CPRD) and Spain (SIDIAP) and secondary care Aarhus database in Denmark in the period 2008-2013. Patients were categorised into frequent exacerbators (FE) (≥2 severe exacerbations in the year following studystart) or non-FE (<2 severe exacerbations). Severe exacerbations were defined as oral corticosteroid course, emergency department visit or hospitalization for asthma. Patient characteristics and asthma-related comorbidities - based on disease codes - were assessed at study start. Differences in characteristics were tested by χ2-test and Mann-Whitney-U-test. Results: The cohorts consisted of 550,512 asthmatics of which 7,545 were FE. In all databases the proportion of FE ranged between 1-3%, and FE were significantly more often female (65-74% vs 57-64%), obese (12-70% vs 9-60%) and had more often severe and uncontrolled asthma than non-FE (p-values <0.05). Also nasal polyposis and gastro-esophageal reflux disease were more frequent in FE, though not significantly in all databases. Conclusion: In a real world setting, we showed low incidence of frequent exacerbators in asthmatics in different countries. FE were more often female and had more asthma-related comorbidities than non-FE. This distinct phenotype provides a target towards personalised asthma management. GSK funded (PRJ2284)