title: Prevalence of airflow limitation in outpatients with cardiovascular diseases in Japan.
abstract: OBJECTIVE
  Cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD) commonly coexist and share common risk factors. The prevalence of COPD in outpatients with a smoking history and CVD in Japan is unknown. The aim of this study was to determine the proportion of Japanese patients with a smoking history being treated for CVD who have concurrent airflow limitation compatible with COPD. A secondary objective was to test whether the usage of lung function tests performed in the clinic influenced the diagnosis rate of COPD in the patients identified with airflow limitation.
  
  
  METHODS
  In a multicenter observational prospective study conducted at 17 centers across Japan, the prevalence of airflow limitation compatible with COPD (defined as forced expiratory volume (FEV)1/FEV6 <0.73, by handheld spirometry) was investigated in cardiac outpatients ≥40 years old with a smoking history who routinely visited the clinic for their CVD. Each patient completed the COPD Assessment Test prior to spirometry testing.
  
  
  RESULTS
  Data were available for 995 patients with a mean age of 66.6±10.0 years, of whom 95.5% were male. The prevalence of airflow limitation compatible with COPD was 27.0% (n=269), and 87.7% of those patients (n=236) did not have a prior diagnosis of COPD. The prevalence of previously diagnosed airflow limitation was higher in sites with higher usage of lung function testing (14.0%, 15.2% respectively) compared against sites where it is performed seldom (11.1%), but was still low.
  
  
  CONCLUSIONS
  The prevalence of airflow limitation in this study indicates that a quarter of outpatients with CVD have COPD, almost all of whom are undiagnosed. This suggests that it is important to look routinely for COPD in CVD outpatients.
authors.affiliation: Onishi Heart Clinic, Mie, Tokyo, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Onishi
authors.affiliation: Medical Affairs Respiratory, GlaxoSmithKline KK, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yoshimoto
authors.affiliation: Independent Consultant, Marbella, Spain.
authors.forename: Gerry W
authors.initials: GW
authors.lastname: Hagan
authors.affiliation: Division of Clinical Science, St George's, University of London, London, UK.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010045:Outpatients / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D015995:Prevalence; 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
keywords: COPD; CVD; diagnosis; handheld spirometer; lung function