Prevalence of chronic obstructive pulmonary disease in Korea - A population-based spirometry survey

Rationale: Although chronic obstructive pulmonary disease is a leading cause of mortality and morbidity worldwide, there are only limited data on its prevalence, especially in Asia. Objectives: A population-based epidemiologic survey of chronic obstructive pulmonary disease in a representative national sample was conducted using spirometry. Methods: A stratified multistage clustered probability design was used to select a nationally representative sample. The survey was performed in conjunction with the second Korean National Health and Nutrition Examination Survey of 9,243 adults over the age of 18 years. The participation rate was 88.8% for questionnaires and 52.1% for spirometry. Results: The prevalence of chronic obstructive pulmonary disease based on Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (a ratio of FEV1 to FVC of less than 0.7) was 17.2% (men, 25.8%; women, 9.6%) among subjects older than 45 years. Among adults of all ages (age > 18 years), the prevalence of airflow obstruction was 7.8% (10.9% in men, 4.9% in women). The majority of these cases were found to be mild in degree, and only a minority of these subjects had received physician diagnosis or treatment. Multivariate analysis revealed that age over 65 years, male sex, smoking more than 20 pack-years, and low income were independent predictors for chronic obstructive pulmonary disease. Conclusions: Seventeen percent of Korean adults over the age of 45 years have mild chronic obstructive pulmonary disease.