Comparison of the prevalence of chronic obstructive pulmonary disease diagnosed by lower limit of normal and fixed ratio criteria.
The Global Initiative of Chronic Obstructive Lung Disease (GOLD) guidelines define chronic obstructive pulmonary disease (COPD) in subjects with FEV(1)/FVC <0.7. However, the use of this fixed ratio may result in over-diagnosis of COPD in the elderly, especially with mild degree of COPD. The lower limit of normal (LLN) can be used to minimize the potential misclassification. The aim of this study was to evaluate the impact of different definitions of airflow obstruction (LLN or fixed ratio of FEV(1)/FVC) on the estimated prevalence of COPD in a population-based sample. We compared the prevalence of COPD and its difference diagnosed by different methods using either fixed ratio (FEV(1)/FVC <0.7) or LLN criterion (FEV(1)/FVC below LLN). Among the 4,816 subjects who had performed spirometry, 2,728 subjects met new ATS/ERS spirometry criteria for acceptability and repeatability. The prevalence of COPD was 10.9% (14.7% in men, 7.2% in women) by LLN criterion and 15.5% (21.8% in men, 9.1% in women) by fixed ratio of FEV(1)/FVC among subjects older than 45 yr. The difference of prevalence between LLN and fixed ratio of FEV(1)/FVC was even higher among subjects with age >/=65, 14.9% and 31.1%, respectively. In conclusion, the prevalence of COPD by LLN criterion was significantly lower in elderly compared to fixed ratio of FEV(1)/FVC. Implementing LLN criterion instead of fixed ratio of FEV(1)/FVC may reduce the risk of over-diagnosis of COPD in elderly people.
Hwang
Yong Il
YI
Department of Internal Medicine, College of Medicine, Hallym University, Chuncheon, Korea.
Kim
Chang Hwan
CH
Kang
Hye-Ryun
HR
Shin
Taerim
T
Park
Sang Myeon
SM
Jang
Seung Hun
SH
Park
Yong Bum
YB
Kim
Cheol Hong
CH
Kim
Dong-Gyu
DG
Lee
Myung Goo
MG
Hyun
In-Gyu
IG
Jung
Ki-Suck
KS
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012306:Risk; D013147:Spirometry