Introduction Asthma and chronic obstructive pulmonary disease (COPD) are both common and usually distinct airway diseases. However, it is now well recognised that many patients, particularly those aged over 55 years, have features of both asthma and COPD [1–5]. This may occur in up to 20% of patients [3]. In recent years there has been intense interest in the coexistence of asthma and COPD, as ...
