Adverse outcomes in young adults with severe asthma: results from the UK Severe Asthma Registry.

Background: Chronic disease in young adults is associated with poor healthcare engagement, poor health-related outcomes and high-risk behaviours. However, there are minimal data regarding the outcomes of young adults with severe asthma. In this study we aimed to assess asthma characteristics and outcomes in young adults aged 16-25 years compared to older age groups. Methods: Using the UK Severe Asthma Registry, we undertook a retrospective observational analysis comparing baseline assessment and annual follow-up data in young adults against other age groups. We investigated differences in medication use, healthcare utilisation, exacerbation rates, lung function, airway inflammation, quality of life and comorbidities using univariate and multivariable analysis. Results: Registry data from 2812 participants was included, including 236 (8.4%) young adults. This age group had the lowest levels of adherence and highest fractional exhaled nitric oxide, highest rates of emergency department attendance and hospitalisation, the second highest rate of intubation, and most frequently reported anxiety and depression. Data from the first annual review confirmed this age group still had the highest rate of emergency department attendance, hospitalisation and the smallest improvement in asthma control. Conclusion: In this cohort, young adults with severe asthma were at a higher risk of poor clinical outcomes when compared to other age groups. The higher rates of emergency treatment and admission and higher levels of airway inflammation suggest that they may experience more severe exacerbations, the reasons for which require further investigation. If a causative link is supported by further work, these findings suggest that age-specific management strategies should be explored towards improving clinical outcomes.