title: Prevalence of chronic obstructive lung disease in Korea using data from the fifth Korea national health and nutrition examination survey.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is the fifth leading cause of death worldwide. The awareness and treatment rate of the disease are low despite its relatively high prevalence. With the added data, this study aimed to identify changes in prevalence and risk factors of COPD using the data from the 5th KNHNES.
  
  
  METHODS
  The subjects of this study were 8,969 individuals aged 40 and older who satisfied suitability and reproducibility for pulmonary function tests. The prevalence, awareness and risk factors of COPD were predicted based on the questionnaires on gender, age, educational level, income level, smoking history, body mass index (BMI) and other COPD related questions.
  
  
  RESULTS
  Diagnosis of COPD was based on the airflow limitation (forced expiratory volume in one second/forced vital capacity <0.7) of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The prevalence of COPD from 2010 to 2012 was 13.7%, of which 23.3% was men and 6.5% women. The prevalence was on the rise, with 12.2% in 2010, 13.2% in 2011, and 15.5% in 2012. In GOLD stage 1, the percentages of those who had cough or sputum and smoking history were 12.1% and 75.5%, respectively, but only 0.1% was diagnosed with COPD. Even after adjusting for asthma and tuberculosis, men, old age, larger amount of smoking were linked with a higher prevalence of COPD, and obese and higher educational level were associated with a lower prevalence of COPD.
  
  
  CONCLUSIONS
  The prevalence of COPD in Korea has been increasing every year, and a higher prevalence was associated with male, older age, more amount of smoking, lower educational level and lower BMI.
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hwayeon
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Se Young
authors.initials: SY
authors.lastname: Jung
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Kiheon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Health Promotion Center, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Bae
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Keehyuck
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Health Promotion Center, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jong-Soo
authors.initials: JS
authors.lastname: Han
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Family Medicine, Seoul National University College of Medicine and Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Seryung
authors.initials: S
authors.lastname: Choo
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin-Mook
authors.initials: JM
authors.lastname: Jeong
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyun-Ray
authors.initials: HR
authors.lastname: Kim
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Ro
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Hansol
authors.initials: H
authors.lastname: Jeong
keywords: Chronic Obstructive Pulmonary Disease; Korea; Prevalence; Pulmonary Function Tests