Chronic obstructive pulmonary disease (COPD) is an important disease from a public health perspective, with a number of preventable occupational, environmental and personal risk factors. The Global Initiative for Obstructive Lung Disease (GOLD) was implemented to raise awareness of COPD and to improve the prevention and treatment of this lung disease.1 A concern has been raised regarding use of the criterion “forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) <0.70” in the definition of GOLD stage I which may lead to overdiagnosis of COPD, particularly in older individuals.2^–5

To address this controversy, Mannino and colleagues assessed COPD-related hospitalisations and mortality among 5201 individuals aged 65 years and older who had participated in the Cardiovascular Health Study.6 The authors concluded that study participants they termed “potentially overdiagnosed” (those with FEV₁/FVC <0.70 who also had an FEV₁/FVC ratio above or equal to the lower limit of normal (LLN)) were …