Updated spirometric reference values for adult Chinese in Hong Kong and implications on clinical utilization.
OBJECTIVE
The accuracy of reference values of lung function is important for assessment of severity and functional impairment of respiratory diseases. The aim of the study was to establish updated prediction formulae of spirometric parameters for Hong Kong Chinese and to compare the reference values with those derived from other studies in white and Chinese subjects.


METHODS
Cross-sectional multicenter study.


METHODS
Lung function laboratories of eight regional hospitals in Hong Kong.


METHODS
Subjects were recruited by random-digit dialing. One thousand one hundred seventy-six subjects who fulfilled recruitment criteria underwent spirometry.


METHODS
Spirometry was performed according to American Thoracic Society recommendations, and the technique was standardized among the eight participating lung function laboratories.


RESULTS
Evaluable data of 1,089 (494 men and 595 women) healthy nonsmokers aged 18 to 80 years were analyzed. Age and height were found to be the major determinants of FEV1 and FVC, with a linear decline of height-adjusted values with age in both sexes. Spirometric values of this population have increased compared to Chinese populations of similar sex, age, and height two decades ago. Reference values derived from white populations were higher than our values by 5 to 19%, and the degree of overestimation varied with age, sex, and lung function parameter. We also demonstrated that the blanket application of correction factors for Asian populations may not be appropriate. In this study cohort, the distribution-free estimation of age-related centiles was more appropriate for the determination of lower limits of normal.


CONCLUSIONS
Our findings underscore the need to use reference values based on updated data derived from local populations or those matched for ethnicity and other sociodemographic characteristics.
Ip
Mary Sau-Man
MS
Department of Medicine, The University of Hong Kong, Queen Mary Hospital. Electronic address: msmip@hkucc.hku.hk.
Ko
Fanny Wai-San
FW
Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital.
Lau
Arthur Chun-Wing
AC
Department of Medicine, Pamela Youde Nethersole Eastern Hospital.
Yu
Wai-Cho
WC
Department of Medicine, Princess Margaret Hospital.
Tang
Kam-Shing
KS
Department of Medicine, Tuen Mun Hospital.
Choo
Kahlin
K
Department of Medicine, Northern District Hospital, Hong Kong SAR, China.
Chan-Yeung
Moira Mo-Wah
MM
Department of Medicine, The University of Hong Kong, Queen Mary Hospital.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005541:Forced Expiratory Volume; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013147:Spirometry; D014797:Vital Capacity