title: The relationship between the COPD Assessment Test score and airflow limitation in Japan in patients aged over 40 years with a smoking history.
abstract: BACKGROUND
  A large number of chronic obstructive pulmonary disease (COPD) patients in Japan remain undiagnosed, primarily due to the underuse of spirometry. Two studies were conducted to see whether the COPD Assessment Test (CAT) in primary care has the potential to identify those patients who need spirometry for a diagnosis of COPD and to determine whether patients with cardiovascular disease had airflow limitation, which could be detected by CAT.
  
  
  METHODS
  Two multicenter, noninterventional, prospective studies (studies 1 and 2) were conducted across Japan. Patients in both studies were ≥40 years old with a smoking history. Those in study 1 were seen in primary care and had experienced repeated respiratory tract infections, but had no diagnosis of COPD. Patients in study 2 were identified in cardiovascular disease clinics when routinely visiting for their cardiovascular disease. All patients completed the CAT prior to lung-function testing by hand-held spirometry. The presence of airflow limitation was defined as a forced expiratory volume in 1 second (FEV1)/FEV6 ratio<0.73.
  
  
  RESULTS
  A total of 3,062 subjects completed the CAT (2,067 in study 1, 995 in study 2); 88.8% were male, and the mean age (±standard deviation) was 61.5±11.6 years. Airflow limitation was found in 400 (19.4%) patients in study 1, and 269 (27.0%) in study 2. The CAT score in patients with airflow limitation was significantly higher than in patients without airflow limitation in both studies: 8.6 (95% confidence interval [CI] 7.9-9.2) versus 7.4 (95% CI 7.1-7.6) in study 1, and 8.3 (95% CI 7.5-9.2) versus 6.4 (95% CI 6.0-6.8) in study 2 (both P<0.001).
  
  
  CONCLUSIONS
  These findings suggest that the CAT has the potential to identify patients with cardiovascular disease or a history of frequent chest infections who need spirometry to diagnose COPD.
authors.affiliation: GlaxoSmithKline, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yoshimoto
authors.affiliation: Division of Respiratory Medicine, Department of Medicine, Shiga University of Medical Science, Otsu, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Nakano
authors.affiliation: Onishi Heart Clinic, Tsu, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Onishi
authors.affiliation: Independent consultant, Marbella, Spain.
authors.forename: Gerry
authors.initials: G
authors.lastname: Hagan
authors.affiliation: Division of Clinical Science, St George's Hospital, University of London, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Jones
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001991:Bronchitis / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D042241:Early Diagnosis; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011320:Primary Health Care; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013147:Spirometry; D011795:Surveys and Questionnaires
keywords: CAT; COPD; airflow limitation; spirometry