Screening for COPD: the gap between logic and evidence

Chronic obstructive pulmonary disease (COPD) is a common disease leading to further morbidity and significant mortality. The first step for any condition is to make the appropriate diagnosis, and spirometry barriers abound in practice around the world. It is tempting to undertake mass screening on all smokers to detect COPD. While this would pick up cases of COPD, results of studies of its effect on COPD end-points such as exacerbations, hospitalisations and mortality are disappointing. As such, aggressive case finding of COPD by screening for symptoms that patients may not themselves perceive is very important in primary care, with subsequent spirometry defining the diagnosis. We also have to separate out population screening from individual patient interactions. Performing spirometry, even on a truly asymptomatic patient, may allow earlier diagnosis and modification of risk factors such as smoking (mostly) and exacerbation risk. It also recognises patients with early disease who are at high risk of comorbidities such as cardiac illness, such that appropriate treatment strategies can be implemented. Making a diagnosis, and even the fact of worrying about such a diagnosis, can affect the motivational level of the individual patient to cease smoking; all patients should of course be counselled to stop smoking. As such, consider the individual patient in front of you for unrecognised symptoms and therefore unrecognised illness, as making a diagnosis earlier can allow the institution of care, including smoking cessation, vaccination, bronchodilators and comorbidity management.