title: Reference ranges for spirometry across all ages: a new approach.
abstract: BACKGROUND
  The Third National Health and Nutrition Examination Survey (NHANES III) reference is currently recommended for interpreting spirometry results, but it is limited by the lack of subjects younger than 8 years and does not continuously model spirometry across all ages.
  
  
  OBJECTIVE
  By collating pediatric data from other large-population surveys, we have investigated ways of developing reference ranges that more accurately describe the relationship between spirometric lung function and height and age within the pediatric age range, and allow a seamless transition to adulthood.
  
  
  METHODS
  Data were obtained from four surveys and included 3,598 subjects aged 4-80 years. The original analyses were sex specific and limited to non-Hispanic white subjects. An extension of the LMS (lambda, mu, sigma) method, widely used to construct growth reference charts, was applied.
  
  
  RESULTS
  The extended models have four important advantages over the original NHANES III analysis as follows: (1) they extend the reference data down to 4 years of age, (2) they incorporate the relationship between height and age in a way that is biologically plausible, (3) they provide smoothly changing curves to describe the transition between childhood and adulthood, and (4) they highlight the fact that the range of normal values is highly dependent on age.
  
  
  CONCLUSIONS
  The modeling technique provides an elegant solution to a complex and longstanding problem. Furthermore, it provides a biologically plausible and statistically robust means of developing continuous reference ranges from early childhood to old age. These dynamic models provide a platform from which future studies can be developed to continue to improve the accuracy of reference data for pulmonary function tests.
authors.affiliation: Portex Respiratory Physiology Unit, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK. s.stanojevic@ich.ucl.ac.uk
authors.forename: Sanja
authors.initials: S
authors.lastname: Stanojevic
authors.forename: Angie
authors.initials: A
authors.lastname: Wade
authors.forename: Janet
authors.initials: J
authors.lastname: Stocks
authors.forename: John
authors.initials: J
authors.lastname: Hankinson
authors.forename: Allan L
authors.initials: AL
authors.lastname: Coates
authors.forename: Huiqi
authors.initials: H
authors.lastname: Pan
authors.forename: Mark
authors.initials: M
authors.lastname: Rosenthal
authors.forename: Mary
authors.initials: M
authors.lastname: Corey
authors.forename: Patrick
authors.initials: P
authors.lastname: Lebecque
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Cole
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001827:Body Height; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009749:Nutrition Surveys; D012016:Reference Values; D013147:Spirometry / Q000706:statistics & numerical data*; D014481:United States