title: Prevalence of obstructive lung disease in a general population sample: the NICECOPD study.
abstract: BACKGROUND
  There are little data available on the prevalence of chronic obstructive pulmonary disease (COPD) in the United Kingdom. The Northern Ireland Cost and Epidemiology of Chronic Obstructive Pulmonary Disease (NICECOPD) study is a two-stage survey to examine the prevalence of obstructive lung disease in a general population sample in the Greater Belfast area.
  
  
  METHODS
  In stage one 4000 subjects aged 40-69 years were selected at random from the general population. They were posted a short screening questionnaire concerning respiratory symptoms. Respondents were divided into 'symptomatic' and 'asymptomatic' groups according to their responses. In stage two, a sample of symptomatic and asymptomatic subjects completed a more intensive assessment that included a detailed questionnaire on medical history, spirometry, skin allergy testing and serial peak flow measurements. Spirometric criteria for airflow obstruction were FEV1/FVC ratio of <70% with FEV1 < 80% predicted. Subjects were assigned diagnoses according to a pre-arranged protocol.
  
  
  RESULTS
  The survey was conducted from May 1999 to May 2001. There was a 67% response rate to the stage 1 screening questionnaire and 1330 responders were identified as being eligible to take part in stage 2. In total, 722 subjects completed a detailed assessment (50.8% Male, symptomatic, n = 326; asymptomatic, n = 396). COPD was diagnosed in 12.3% (8.8, 15.8) of the symptomatic and 2.2% (0.8, 3.6) of the asymptomatic group. The estimated prevalence of obstructive lung disease in the total population age 40-69 years was 14.4%: 6.3% COPD; 7.2% asthma; 0.9% with indeterminate airflow obstruction. In men, the prevalence of COPD varied from 4.9% in those aged 40-49 years to 12.3% in those aged 60-69 years and in women, varied from 1.4% in 40-49 years of age to 4.5% in 60-69 years.
  
  
  CONCLUSIONS
  The data suggest that COPD and asthma are common conditions in the general population and should inform future plans to address the burden of disease.
authors.affiliation: Regional Respiratory Centre, Belfast City Hospital, N. Ireland.
authors.forename: Eoin
authors.initials: E
authors.lastname: Murtagh
authors.forename: Liam
authors.initials: L
authors.lastname: Heaney
authors.forename: Jenny
authors.initials: J
authors.lastname: Gingles
authors.forename: Richard
authors.initials: R
authors.lastname: Shepherd
authors.forename: Frank
authors.initials: F
authors.lastname: Kee
authors.forename: Chris
authors.initials: C
authors.lastname: Patterson
authors.forename: Joe
authors.initials: J
authors.lastname: MacMahon
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D011897:Random Allocation; D012882:Skin Tests; D013147:Spirometry; D011795:Surveys and Questionnaires