Impact of comorbidities on EQ-5D quality-of-life index in severe asthma

Abstract

BackgroundSevere asthma pathology encompasses a wide range of pulmonary and extra-pulmonary treatable traits with a high prevalence of comorbidities. Although asthma-specific health related quality of life measures are most sensitive to changes in asthma control, generic measures, such as EQ-5D-5L (EuroQol 5-Dimension 5-Level questionnaire), are potentially better for capturing the impact of comorbidities. ObjectiveTo examine the impact of pulmonary and extra-pulmonary treatable traits on quality of life at initial severe asthma assessment, and to compare the characteristics of those patients whose quality of life does and does not improve during follow-up at severe asthma centres. MethodsPatients characteristics at baseline assessment within the UK Severe Asthma Registry were compared by EQ-5D-5L utility index quartile. Patients with follow-up review data were stratified by change in EQ-5D-5L utility index from baseline to follow-up, and characteristics similarly examined. ResultsPatients in the quartiles with worst dysutility at baseline were observed to exhibit more treatable traits and in particular extra-pulmonary traits associated with cumulative systemic corticosteroids, including obesity, anxiety/depression, and osteoporosis. In those patients whose quality of life improved over follow-up, a reduction in exacerbations, uncontrolled symptoms and requirement for maintenance oral corticosteroids (OCS) was observed. ConclusionBoth pulmonary and extra-pulmonary treatable traits are important determinants of quality of life in severe asthma. Comorbidities associated with cumulative systemic corticosteroid exposure are particularly associated with worse quality of life, emphasising the importance of early identification and management of severe asthma before comorbidities develop.