Asthma and Type 2 Comorbidities - Real-life Characterisation of Patients with Active Asthma and Type 2 Asthma Comorbidities

Asthma is a common long-term condition which is responsible for considerable morbidity, mortality and costs. There are several related conditions, involving type 2 inflammation which have been identified as affecting asthma outcomes. The nine T2 co-morbidities of interest are: eczema, allergic rhinitis, chronic rhinosinusitis, nasal polyps, urticaria, allergic conjunctivitis, food allergy, eosinophilic oesophagitis and anaphylaxis. Because of the common underlying disease process, it has been suggested that successful treatment of one might also improve related conditions.The frequency with which these conditions co-occur in patients with asthma has not yet been described, nor has the relationship between co-morbidity patterns with asthma severity and asthma-related resource utilisation.The aim of this study is to describe the frequency and interrelations of these conditions, and assess associations with asthma severity, asthma-related healthcare resource utilisation and costs, within a real-world asthma population.The prevalence of each co-morbidities pattern will be measured, and associations between co-morbidities described using likelihood ratios and principal component analysis. This will be used to select a subset of patterns, in which patient characteristics, asthma severity, healthcare resource utilisation and cost will be compared using multivariable regression models, in all patients and stratified by asthma severity, co-morbidity severity and activity, blood eosinophil count and age.