The local prevalence of COPD by post-bronchodilator GOLD criteria in Korea

Chronic obstructive pulmonary disease (COPD) is a disease characterised by not fully reversible airflow limitation. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) committee decided to diagnose COPD using post-bronchodilator spirometry values. We aimed to examine the prevalence and risk factors of COPD in Ansan, an industrialised city of Korea, by using the post-bronchodilator GOLD criteria. We then investigated the implications of brenchodilation on the prevalence of COPD.

A total of 3642 participants in the Korean Health and Genome Study were interviewed about age, income, smoking status and respiratory symptoms and completed pulmonary function tests, including postbronchodilator spirometry.

COPD prevalence by post-bronchodilator spirometry was 3.7% (134/3642), which was significantly different from that estimated using pre-bronchodilator criteria (7.7%, 282/3642). Exclusion of subjects with significant bronchodilator response (BDR) significantly lowered the prevalence of COPD to 3.3% (117/3572), compared with including subjects with post-bronchodilatory residual obstruction with significant BDR. Prevalence was associated with old age, smoking history, male sex and respiratory symptoms.

COPD prevalence by post-bronchodilator GOLD criteria was 3.7%, which was much lower than that of pre-bronchodilator criteria. The bronchodilator reversibility test substantially affects estimations of COPD prevalence.