title: Prevalence, diagnosis and relation to tobacco dependence of chronic obstructive pulmonary disease in a nationally representative population sample.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is the fourth most common cause of death worldwide. It is caused primarily by cigarette smoking. Given its importance, it is remarkable that reliable national prevalence data are lacking for most countries. This study provides estimates of the national prevalence of COPD in England, the extent of under-detection of the disorder, and patterns of cigarette smoking, dependence, and motivation to stop smoking in those with the disease.
  
  
  METHODS
  Data from 8215 adults over the age of 35 who participated in the Health Survey for England were analysed. Information was obtained on self-reported and cotinine validated smoking status, cigarette dependence, motivation to stop smoking, COPD defined by spirometry using joint American Thoracic Society and European Respiratory Society criteria, and self-reports of diagnosis with respiratory disorders.
  
  
  RESULTS
  Spirometry-defined COPD was present in 13.3% (95% CI 12.6 to 14.0) of participants, over 80% of whom reported no respiratory diagnosis. Even among people with severe or very severe COPD by spirometric assessment, only 46.8% (95% CI 39.1 to 54.6) reported any diagnosed respiratory disease. A total of 34.9% (95% CI 32.1 to 37.8) of people with spirometry-defined COPD were smokers compared with 22.4% (95% CI 21.4 to 23.4) of those without, and smoking prevalence increased with disease severity. Smokers with spirometry-defined COPD were more cigarette dependent but had no greater desire to quit than other smokers.
  
  
  CONCLUSIONS
  COPD is common among adults in England and is predominantly undiagnosed. In smokers it is associated with higher degrees of cigarette dependence but not with a greater motivation to stop smoking.
authors.affiliation: Cancer Research Health Behaviour Unit, Department of Epidemiology and Public Health, University College London, London WC1E 6BT, UK. lion.shahab@ucl.ac.uk
authors.forename: L
authors.initials: L
authors.lastname: Shahab
authors.forename: M J
authors.initials: MJ
authors.lastname: Jarvis
authors.forename: J
authors.initials: J
authors.lastname: Britton
authors.forename: R
authors.initials: R
authors.lastname: West
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013147:Spirometry; D014029:Tobacco Use Disorder / Q000150:complications / Q000453:epidemiology*