title: Chronic obstructive pulmonary disease in older persons: A comparison of two spirometric definitions.
abstract: BACKGROUND
  Among older persons, we previously endorsed a two-step spirometric definition of chronic obstructive pulmonary disease (COPD) that requires a ratio of forced expiratory volume in 1sec to forced vital capacity (FEV(1)/FVC) below .70, and an FEV(1) below the 5th or 10th standardized residual percentile ("SR-tile strategy").
  
  
  OBJECTIVE
  To evaluate the clinical validity of an SR-tile strategy, compared to a current definition of COPD, as published by the Global Initiative for Obstructive Lung Disease (GOLD-COPD), in older persons.
  
  
  METHODS
  We assessed national data from 2480 persons aged 65-80 years. In separate analyses, we evaluated the association of an SR-tile strategy with mortality and respiratory symptoms, relative to GOLD-COPD. As per convention, GOLD-COPD was defined solely by an FEV(1)/FVC<.70, with severity staged according to FEV(1) cut-points at 80 and 50 percent predicted (%Pred).
  
  
  RESULTS
  Among 831 participants with GOLD-COPD, the risk of death was elevated only in 179 (21.5%) of those who also had an FEV(1)<5th SR-tile; and the odds of having respiratory symptoms were elevated only in 310 (37.4%) of those who also had an FEV(1)<10th SR-tile. In contrast, GOLD-COPD staged at an FEV(1) 50-79%Pred led to misclassification (overestimation) in terms of 209 (66.4%) and 77 (24.6%) participants, respectively, not having an increased risk of death or likelihood of respiratory symptoms.
  
  
  CONCLUSIONS
  Relative to an SR-tile strategy, the majority of older persons with GOLD-COPD had neither an increased risk of death nor an increased likelihood of respiratory symptoms. These results raise concerns about the clinical validity of GOLD guidelines in older persons.
authors.affiliation: Yale University School of Medicine, Department of Internal Medicine, New Haven, CT 06516, 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: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000401:mortality; D013147:Spirometry / Q000145:classification* / Q000379:methods