title: [Comparison of spirometric reference values in Chilean children].
abstract: BACKGROUND
  The interpretation of lung function tests must be based on reference normal values obtained in the same population. In Chile an expert panel recommended the use of values obtained by, Gutierrez el al locally, that are higher than those obtained by Knudson, for forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1).
  
  
  OBJECTIVE
  To analyze the clinical application of both reference values in a selected population.
  
  
  METHODS
  Retrospective review of 499 spirometries done in our laboratory to 285 males and 214 females, aged 4.5 to 18 years. The reports using either Gutierrez (G) or Knudson (K) reference values were compared. The 5th percentile was considered the inferior limit for normality.
  
  
  RESULTS
  The height range of patients was 110-178 cm (median 130, 3rd quartile 143). Referral diagnoses were probable asthma in 349 (70%), asthma in 119 (24%), to rule out restrictive disease in 12 (2%) and others 19 (4%). FEV1/FVC ratio was > or =84% in 290 patients. Using K values, lung function was interpreteed as within normal limtits in 321 patients (64.3%), as mild obstructive disease (MOD) in 171 (34.3%), as combined limitation (CL) in 2, mild restrictive disease (MRD), moderate restrictive disease (MR) and severe restrictive disease (SRD) in 1 patient each. Using G values, lung function was interpreted as within normal limits in 133 patients (26.7%), MOD in 343 (68.7%), MRD in 6, CL. in 4 and MR in 2. In 193 spirometries (39%) there was lack of concordance between the interpretations using K or G values.
  
  
  CONCLUSIONS
  There is a wide rante of variability when G or K values are used to interpret lung function in children in Chile. Redefinition of local standards would be necessary.
authors.affiliation: Departamento de Pediatría, Pontificia Universidad Católica de Chile. Santiago, Chile.
authors.forename: Cecilia G
authors.initials: CG
authors.lastname: Alvarez
authors.forename: Pablo V
authors.initials: PV
authors.lastname: Brockmann
authors.forename: Pablo N
authors.initials: PN
authors.lastname: Bertrand
authors.forename: Solange L
authors.initials: SL
authors.lastname: Caussade
authors.forename: Eugenia M
authors.initials: EM
authors.lastname: Campos
authors.forename: Ignacio D
authors.initials: ID
authors.lastname: Sánchez
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D002677:Chile; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D012016:Reference Values; D012189:Retrospective Studies; D013147:Spirometry; D014797:Vital Capacity