Patients with chronic obstructive pulmonary disease (COPD) are diagnosed by a combination of symptoms and abnormal pulmonary function studies. The severity of disease is defi ned by the degree of abnormality noted on their pulmonary function studies. The stage of disease is categorized by a system defi ned by the Global Initiative for Chronic Obstructive Disease commonly referred to as the GOLD criteria.
There are 5 stages in the GOLD system (1) mild, (2) moderate, (3) severe and (4) very severe. There is, however, a stage called GOLD (0). GOLD (0) is defi ned as a patient with symptoms of cough and phlegm production but with normal lung function on pulmonary function testing. As I have stated, for diagnosis COPD patients must have fi xed abnormalities on their pulmonary function tests. What is the signifi cance of a patient with symptoms but normal tests? This is an issue that has been debated in the industry for some time. One explanation is that the range of normal for the values on pulmonary function testing is large. A patient may be found to be at the lower range of normal but really should be at the upper end and it may take some additional time (since COPD is progressive) to drop into the abnormal range.
The question at this point is what do we do with patients in GOLD (0)? Obviously, smoking cessation is needed, and perhaps some help with airway infl ammation. These patients need to be followed and treatment advanced as their disease progresses.