Impact of comorbidities on clinical outcomes in severe asthma- an analysis from the Swiss severe asthma registry

<bold>Background:</bold> Asthma is a chronic airway disease, affecting over 300 million people worldwide. 5-10% of patients suffer from severe asthma. Availability of data about the clinical course and the role of comorbidities in severe asthma is insufficient. <bold>Objectives:</bold> This study investigates the role of comorbidities in asthma related outcomes. <bold>Method:</bold> The SSAR is an ongoing, multicentre, cohort study that includes patients with severe asthma. Recruitment of patients is ongoing. For the analysis we used prospective data from 180 patients, included in the SSAR between 2019 and 2021. <bold>Results:</bold> No significant increase in the prevalence of comorbidities was observed during the follow-up period. The number of patients without exacerbations in the overall population increased significantly (BL 44% vs. FU2 74%, < 0.001). Further, the ANOVA revealed significant increase in quality of life (p < 0.001) and asthma control (p = 0.029). A concurrent significant decrease in FEV1/FVC value (p = 0.014) but not in other diagnostic biomarkers was observed. GERD led to a significant mean decrease of asthma control (p = 0.037), whereas allergies and COPD led to a significant mean decrease of quality of life (p = 0.016 and p = 0.027 respectively). <bold>Conclusion:</bold> The influence of comorbidities on asthma related outcomes may be smaller than assumed. However, future analysis have to include more co-variates in the model.