Screening for and early detection of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a substantially underdiagnosed disorder, with the diagnosis typically missed or delayed until the condition is advanced. Spirometry is the most frequently used pulmonary function test and enables health professionals to make an objective measurement of airflow obstruction and assess the degree to which it is reversible. As a diagnostic test for COPD, spirometry is a reliable, simple, non-invasive, safe, and non-expensive procedure. Early diagnosis of COPD should provide support for smoking cessation initiatives and lead to reduction of the societal burden of the disease, but definitive confirmation of both proves elusive. Despite substantial effort and investment, implementation of quality spirometry is deficient because of several hurdles and limitations, described in this Review. All in all, spirometry is recognised as the essential test for diagnosis and monitoring of COPD.