The German severe asthma patient: Baseline characteristics of patients in the German Severe Asthma Registry, and relationship with exacerbations and control

Introduction: The German Asthma Net Severe Asthma Registry is collecting long-term data from a large cohort of patients aged ≥6 years with severe asthma. This manuscript presents their baseline characteristics, and identifies relationships with exacerbations and/or poor asthma control.

Methods: The registry is collecting routine clinical parameters including: demographics and medical history; disease characteristics (Asthma Control Questionnaire [ACQ]-5, forced expiratory volume in 1 s [FEV₁]); exacerbations; and biomarkers (eosinophils, immunoglobulin E [IgE], fractional exhaled nitric oxide [FeNO]).

Results: These analyses include data from 2011 patients at 72 sites (91.9% adult). Children (6-17 years) were more likely to be male, whereas more adults were female (males: children/adults 62%/41%). Most were receiving inhaled corticosteroid/long-acting β₂-agonist combinations (78%/81%); 38.0% of adults were receiving systemic steroids. Asthma control was suboptimal in both groups: 21.5%/13.3% were controlled; 10.4%/49.1% were symptomatic; 33.1%/37.2% received emergency asthma treatment in the previous year. Median blood eosinophil (400/238 cells/μL) and IgE levels (494/186 IU/mL) were higher in children; FeNO was lower (19/35 ppb). Patients with ≥2 exacerbations in the previous year had lower FEV₁ (absolute and % predicted) and IgE, and higher ACQ-5, FeNO and blood eosinophil levels (all p < 0.05). There was a weak, negative correlation between ACQ-5 and FEV₁% predicted in adults (p < 0.001).

Conclusions: These analyses characterise the typical German patient with severe asthma, and provide information on their overall care. Their planned long-term follow-up will assess whether asthma control can be optimised, how best to do so, and most importantly how such optimisation can benefit patients.