title: Comparison of spirometry criteria for the diagnosis of COPD: results from the BOLD study.
abstract: Published guidelines recommend spirometry to accurately diagnose chronic obstructive pulmonary disease (COPD). However, even spirometry-based COPD prevalence estimates can vary widely. We compared properties of several spirometry-based COPD definitions using data from the international Burden of Obstructive Lung Disease (BOLD)study. 14 sites recruited population-based samples of adults aged > or =40 yrs. Procedures included standardised questionnaires and post-bronchodilator spirometry. 10,001 individuals provided usable data. Use of the lower limit of normal (LLN) forced expiratory volume in 1 s (FEV(1)) to forced vital capacity (FVC) ratio reduced the age-related increases in COPD prevalence that are seen among healthy never-smokers when using the fixed ratio criterion (FEV(1)/FVC <0.7) recommended by the Global Initiative for Chronic Obstructive Lung Disease. The added requirement of an FEV(1) either <80% predicted or below the LLN further reduced age-related increases and also led to the least site-to-site variability in prevalence estimates after adjusting for potential confounders. Use of the FEV(1)/FEV(6) ratio in place of the FEV(1)/FVC yielded similar prevalence estimates. Use of the FEV(1)/FVC<LLN criterion instead of the FEV(1)/FVC <0.7 should minimise known age biases and better reflect clinically significant irreversible airflow limitation. Our study also supports the use of the FEV(1)/FEV(6) as a practical substitute for the FEV(1)/FVC.
authors.affiliation: Kaiser Permanente, Center for Health Research, Portland, OR 97227-1110, USA. william.vollmer@kpchr.org
authors.forename: W M
authors.initials: WM
authors.lastname: Vollmer
authors.forename: Thorn
authors.initials: T
authors.lastname: Gíslason
authors.forename: P
authors.initials: P
authors.lastname: Burney
authors.forename: P L
authors.initials: PL
authors.lastname: Enright
authors.forename: A
authors.initials: A
authors.lastname: Gulsvik
authors.forename: A
authors.initials: A
authors.lastname: Kocabas
authors.forename: A S
authors.initials: AS
authors.lastname: Buist
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013147:Spirometry; D011795:Surveys and Questionnaires; D014797:Vital Capacity