title: Reference standards for forced expiratory indices in Chinese preschool children.
abstract: Spirometric testing is traditionally achievable in children of school-age and beyond. Incorporation of interactive incentives motivates preschool children to facilitate measurement of forced expiratory indices. Validated spirometric reference standards are available for Caucasian preschoolers but lacking in Asians. We established spirometric references in Chinese children aged 2-7 years, who were recruited from 19 randomly selected nurseries and kindergartens in Hong Kong. Parents completed International Study of Asthma and Allergies in Childhood questionnaire, and children concurrently performed incentive spirometry on-site according to international guideline. Prediction equations for spirometric indices were formulated by linear regression. One thousand four hundred two (72.9%) of 1,922 consented children, with mean (SD) age 4.4 (1.0) years, successfully performed spirometry. Following exclusions due to medical and technical reasons, 895 (63.8%) children contributed spirometric data to our references. Girls had lower FEV0.5 , FEV0.75 , FEV1 , FVC, and PEF but similar FEF25-75 than boys, adjusted for age, weight, and standing height as covariates. Standing height was the most important predictor for FEV0.5 , FEV0.75 , FEV1 , FVC, and PEF in both boys (adjusted R(2) 0.525-0.734) and girls (adjusted R(2) 0.583-0.721), whereas the best prediction model for both gender is formed by standing height, weight, and age. At various standing heights, our preschoolers had FEV1 Z-scores 0.13-1.00 higher than those of collaborative Caucasian reference. This study justifies the need for ethnic-specific reference equations and presents spirometry references in young Chinese children. Their forced expiratory indices are determined by gender, age, weight and standing height, and standing height is the best anthropometric index to predict all spirometric indices.
authors: Department of Pediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong. tfleung@cuhk.edu.hk.
authors: Ting F
authors: TF
authors: Leung
authors: Tak C
authors: TC
authors: Liu
authors: Kwok K
authors: KK
authors: Mak
authors: Xuefen
authors: X
authors: Su
authors: Hing Y
authors: HY
authors: Sy
authors: Albert M
authors: AM
authors: Li
authors: Joseph T F
authors: JT
authors: Lau
authors: Sooky
authors: S
authors: Lum
authors: Gary W K
authors: GW
authors: Wong
mesh_terms: D044466:Asian People; D002648:Child; D002675:Child, Preschool; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D012015:Reference Standards; D013147:Spirometry
keywords: Chinese; preschool; pulmonary function test; reference; spirometry