title: Development of reference equations for spirometry in Japanese children aged 6-18 years.
abstract: BACKGROUND
  Spirometry is the most widely used pulmonary function test and the measured values of spirometric parameters need to be evaluated using reference values predicted for the corresponding race, sex, age, and height. However, none of the existing reference equations for Japanese children covers the entire age range of 6-18 years. The Japanese Society of Pediatric Pulmonology had organized a working group in 2006, in order to develop a new set of national standard reference equations for commonly used spirometric parameters that are applicable through the age range of 6-18 years.
  
  
  METHODS
  Quality assured spirometric data were collected through 2006-2008, from 14 institutions in Japan. We applied multiple regression analysis, using age in years (A), square of age (A(2)), height in meters (H), square of height (H(2)), and the product of age and height (AH) as explanatory variables to predict forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV(1)), peak expiratory flow (PEF), forced expiratory flow between 25% and 75% of the FVC (FEF(25-75%)), instantaneous forced expiratory flow when 50% (FEF(50%)) or 75% (FEF(75%)) of the FVC have been expired.
  
  
  RESULTS
  Finally, 1,296 tests (674 boys, 622 girls) formed the reference data set. Distributions of the percent predicted values did not differ by ages, confirming excellent fit of the prediction equations throughout the entire age range from 6 to 18 years. Cut-off values (around 5 percentile points) for the parameters were also determined.
  
  
  CONCLUSIONS
  We recommend the use of this new set of prediction equations together with suggested cut-off values, for assessment of spirometry in Japanese children and adolescents.
authors.affiliation: Committee on Pulmonary Function Testing, Japanese Society of Pediatric Pulmonology, Tokyo, Japan. mtakase@nms.ac.jp
authors.forename: Masato
authors.initials: M
authors.lastname: Takase
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakata
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shikada
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Tatara
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Fukushima
authors.forename: Tomoo
authors.initials: T
authors.lastname: Miyakawa
mesh_terms: D000293:Adolescent; D044466:Asian People; D002648:Child; D005260:Female; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008433:Mathematics; D011446:Prospective Studies; D012016:Reference Values; D013147:Spirometry / Q000706:statistics & numerical data*