Lay summary
Airways disease is currently separated into asthma and COPD (which includes chronic bronchitis and emphysema). In the community people with airways disease differ in the way the disease manifests itself. Most have one of several patterns of airways disease that have some features of classical asthma and some features of classical COPD. The best medication regime for each of these patterns or groups of airways disease is not known so many will not be receiving optimal treatment. We have recently used the technique of cluster analysis to identify not two but five groups of airways disease. In this proposed study, we will undertake a further cluster analysis in a larger sample to validate this new classification. We will determine the clinical relevance of the new classification by comparing how the groups respond to standard bronchodilator and inhaled corticosteroid treatments. This information will guide doctors who are treating these diseases.