Complex airway disease: an approach to assessment and management.

Research into new treatments for airway disease focuses on severe disease because morbidity, mortality, and health-care costs are substantial and the unmet need is greatest. One reason why outcomes are poor in these patients could be that the clinical expression of disease is heterogeneous and difficult to classify. As a result, guideline-based management algorithms fail. Additionally, difficulties with disease classification and misconceptions about the relation between different aspects of severe airway disease have hindered new drug development. A potential solution is to use a new approach to assess severe airway disease, which moves the diagnostic focus from categorisation of patients to identification and characterisation of the main drivers of disease. This approach will help rather than hinder identification of clinically important phenotypes of disease and will facilitate the development of new phenotype-specific treatment options.