title: The Risk Factors and Characteristics of COPD Among Nonsmokers in Korea: An Analysis of KNHANES IV and V.
abstract: Chronic obstructive pulmonary disease (COPD) is increasing in prevalence and mortality. This study evaluated the prevalence, risk factors, characteristics, and health-related quality of life (HRQoL) of COPD among nonsmokers in Korea.
  
  
  
  This was a population-based cross-sectional study using data obtained from the Fourth and Fifth Korean National Health and Nutrition Examination Survey, which was conducted from 2007 to 2011.
  
  
  
  A total of 15,063 participants completely answered the questionnaire and performed the spirometry. Among them, 59.6 % were nonsmokers and 40.4 % were smokers. The prevalence of nonsmoker COPD was 7.1 %. On multivariate analysis, age ≥65 years (OR, 2.93; 95 % CI, 2.44-3.51), male sex (OR, 2.98; 95 % CI, 2.40-3.71), living in rural area (OR, 1.26; 95 % CI, 1.05-1.51), lower body mass index (BMI) (<18.5 kg/m(2)) (OR, 3.00; 95 % CI, 1.78-5.01), self-reported asthma (OR, 2.72; 95 % CI, 2.05-3.60), and self-reported tuberculosis (OR, 4.73; 95 % CI, 3.63-6.17) showed a significantly higher risk of nonsmoker COPD. Analysis of nonsmoker and smoker COPD revealed that there are more females in nonsmoker COPD patients (73.9 vs. 6.9 %, P < 0.001). Nonsmoker COPD patients presented with impaired mobility, pain/discomfort, and anxiety/depression functions as well as a lower mean EuroQol Five-Dimension Questionnaire utility score, which showed HRQoL.
  
  
  
  The burden of nonsmoker COPD was considerable. Older age, male sex, lower BMI, self-reported asthma, and self-reported tuberculosis were risk factors for nonsmoker COPD and there were differences between nonsmoker and smoker COPD in terms of sex, comorbidities, and HRQoL.
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Su Hwan
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Eu Dong
authors.initials: ED
authors.lastname: Hwang
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Ju Eun
authors.initials: JE
authors.lastname: Lim
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Moon
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Young Ae
authors.initials: YA
authors.lastname: Kang
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Ji Ye
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Moo Suk
authors.initials: MS
authors.lastname: Park
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Se Kyu
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Joon
authors.initials: J
authors.lastname: Chang
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea.
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Korea. dobie@yuhs.ac.
authors.forename: Song Yee
authors.initials: SY
authors.lastname: Kim
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001007:Anxiety / Q000453:epidemiology; D001249:Asthma / Q000453:epidemiology; D015992:Body Mass Index; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009749:Nutrition Surveys; D010146:Pain / Q000453:epidemiology; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000503:physiopathology*; D011788:Quality of Life; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology*; D013147:Spirometry; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology; D014505:Urban Population / Q000706:statistics & numerical data
keywords: Chronic obstructive pulmonary disease; Never-smoker; Nonsmoker; Population study; Quality of life