Identification of treatable traits in a severe asthma registry: prevalence and exacerbation predictors

Background: A new taxonomic and management approach, termed treatable traits, has been proposed for airway diseases including severe asthma. This study examined whether treatable traits could be assessed using registry data, the prevalence of traits in severe and non-severe asthma, and whether particular treatable traits were associated with future exacerbation risk. Methods: The Australasian Severe Asthma Web-based Database (SAWD) enrolled 434 participants with severe asthma and a comparison group of 102 with non-severe. Published treatable traits were mapped to registry data fields and their prevalence described. Participants were characterised at baseline and each 6 months for 24 months. Results: In SAWD, 24 treatable traits were identified in three domains: pulmonary (7 traits), extrapulmonary (13 traits) and behavioural/risk-factors (4 traits). People with severe asthma expressed more pulmonary and extrapulmonary treatable traits than non-severe asthma. Allergic sensitisation, upper-airway disease, airflow limitation, eosinophilic inflammation and frequent exacerbations were common in severe asthma. Ten traits predicted exacerbation risk; among the strongest were being exacerbation prone (IRR 2.07 (1.66, 2.58), depression (IRR 1.63 (1.31, 1.88), inhaler-device polypharmacy (IRR 1.51 (1.31, 1.75), vocal cord dysfunction (IRR 1.51 (1.22, 1.88) and obstructive sleep apnoea (IRR 1.41 (1.05, 1.89). Conclusion: Treatable traits can be assessed using severe asthma registry data. In severe asthma, patients express more treatable traits than non-severe asthma. Traits may be associated with future asthma exacerbation risk demonstrating clinical utility of assessing treatable traits.