Chronic obstructive pulmonary disease in older persons: A comparison of two spirometric definitions.
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.
Vaz Fragoso
Carlos A
CA
Yale University School of Medicine, Department of Internal Medicine, New Haven, CT 06516, USA. carlos.fragoso@yale.edu
Concato
John
J
McAvay
Gail
G
Van Ness
Peter H
PH
Rochester
Carolyn L
CL
Yaggi
H Klar
HK
Gill
Thomas M
TM
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