Definition of Chronic Obstructive Pulmonary Disease (COPD): Is the Latest GOLD Classification of Severity Still Valid?

Abstract

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response evoked by the presence of noxious particles or gases in the airways. The progression of airflow limitation has a tremendous impact on disease severity and overall prognosis. However, other factors, such as symptoms, exacerbations, or comorbidities, also have a considerable impact on individual COPD patients. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) Scientific Committee launched a joint project between the World Health Organization and the National Heart, Lung, and Blood Institute. The initial report of the GOLD guideline for COPD was published in 2001. Since then, the GOLD Scientific Committee has kept the GOLD guideline updated by revising it on the basis of the latest scientific evidence. Although the GOLD classification was initially based on the severity of airflow limitation, the classification of symptoms, breathlessness, and risk of exacerbations as well as spirometry results was recently included because of the accumulated scientific evidence. In this chapter, we will define COPD and discuss the latest GOLD classification.