Abstract
General practitioners find it difficult to accurately distinguish asthma from COPD. However, this differential diagnosis is important, as the treatment of the two entities is different. Asthma is by definition steroid responsive, whereas several long-term trials have demonstrated that in COPD, the lung function is not affected by steroid treatment. Yet it is questionable whether lung function is a good parameter for evaluating treatment effects, as there are indications that steroids affect the quality of life and the number of exacerbations. Moreover, an observational study has shown that inhaled steroids might affect mortality. Observational studies do not normally provide conclusive evidence, due to the possible inclusion of many confounding factors (such as confounding by indication). Nevertheless, this observational study indicates that it might be possible to treat COPD with steroids. A large prospective randomised trial that is currently in progress will need to confirm whether or not this is the case.
