To the Editor:
I thank P. Sterk for an interesting and informative Editorial on the definition and classification of patients with chronic obstructive pulmonary disease (COPD) 1. However, I cannot help but get the feeling from reading the article that perhaps most, if not all, of the emphasis is placed on post-bronchodilator spirometric values. As pointed out by Sterk 1, COPD is a disease where airflow limitation is not fully reversible. Taking this into account, one would intuitively expect that the definition and classification of COPD should at least be based on three criteria: namely, pre- and post-bronchodilator spirometric values, and the degree of reversibility between the two values; rather than depending solely on post-bronchodilator values. Would it not be meaningless tohave just a post-bronchodilator value without its pre-bronchodilator counterpart, as significant reversibility wrongly diagnosed as fixed airflow limitation, as pointed out by Sterk 1, may lead to potential over-diagnosis and over-estimation of the severity of patients with COPD? It would perhaps be sensible if reporting of future articles relating to research on patients with COPD incorporated both the pre- and post-bronchodilator values, together with the degree of reversibility.
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