Age- and sex-dependent differences in patients with severe asthma included in the German Asthma Net cohort

Background: Severe asthma affects less than 5% of asthmatics, but is associated with high costs and increased mortality. The aim of this study was to assess age- and sex-dependent differences in this patient group. Methods: Retrospective analysis of 1317 children and adults with severe asthma who are included in the German Asthma Net registry. Results: There were more adults than children in the registry and patients' mean age was 52. Apart from children <18 years, there were more women (57%) than men. The age of first diagnosis ranged from 0 to 76 years. 38% of patients had a positive bronchial reversibility after short acting bronchodilators. Quality of life, FEV1 and MEF 25 decreased with older age whereas treatment with oral steroids and monoclonal antibodies increased. An antieosinophil treatment was most frequently used in patients aged around 57 years, while an anti-IgE treatment was used in all age-groups including children. There were sex-dependent differences with lower values in men for FEV1, FVC, MEF 25 and DLCO. Yet, women were more frequently unable to work than men due to the disease. Conclusion: In patients with severe asthma, clinical characteristics, but also treatments differed between age groups and between the sexes, reflecting different phenotypes of the disease.