title: Defining chronic obstructive pulmonary disease in older persons.
abstract: OBJECTIVE
  To develop a more age-appropriate spirometric definition of chronic obstructive pulmonary disease (COPD) among older persons.
  
  
  METHODS
  Using data from the Third National Health and Nutrition Examination Survey (NHANES III), we developed a two-part spirometric definition of COPD in older persons, aged 65-80 years, that 1) determines a cut-point for the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) based on mortality risk; and 2) among persons below this critical FEV1/FVC threshold, determines cut-points for the FEV1, expressed as a standardized residual percentile (SR-tile) and based on the prevalence of respiratory symptoms and mortality risk. Measurements included spirometry, health questionnaires, and mortality (National Death Index).
  
  
  RESULTS
  There were 2480 older participants with a mean age of 71.7 years; 1372 (55.4%) had a smoking history, 1097 (44.2%) had respiratory symptoms and, over the course of 12-years, 868 (35.0%) had died. Among participants with an FEV1/FVC<.70 and FEV1<5th SR-tile, representing 7.7% of the cohort, the risk of death was doubled (adjusted hazard ratio, 2.01; 95% confidence interval [CI], 1.60-2.54). Among participants with an FEV1/FVC<.70 and FEV1<10th SR-tile, representing 13.4% of the cohort, the prevalence of respiratory symptoms was elevated (adjusted odds ratio, 2.44; CI, 1.79-3.33).
  
  
  CONCLUSIONS
  In a large, nationally representative sample of community-living older persons, defining COPD based on an FEV1/FVC<.70, with FEV1 cut-points at the 10th and 5th SR-tiles, identifies individuals with an increased prevalence of respiratory symptoms and an increased risk of death, respectively.
authors.affiliation: Claude D. Pepper Older Americans Independence Center, Yale University, New Haven, CT, USA. carlos.fragoso@yale.edu
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Vaz Fragoso
authors.forename: John
authors.initials: J
authors.lastname: Concato
authors.forename: Gail
authors.initials: G
authors.lastname: McAvay
authors.forename: Peter H
authors.initials: PH
authors.lastname: Van Ness
authors.forename: Carolyn L
authors.initials: CL
authors.lastname: Rochester
authors.forename: H Klar
authors.initials: HK
authors.lastname: Yaggi
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gill
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D017410:Practice Guidelines as Topic; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000503:physiopathology; D012737:Sex Factors; D013147:Spirometry