title: Exercise challenge test: is a 15% fall in FEV(1) sufficient for diagnosis?
abstract: BACKGROUND
  In the exercise challenge test (ECT), a drop in forced expiratory volume in the first second (FEV(1)) of between 10 and 15% is the determinant variable for a diagnosis of exercise-induced bronchospasm.
  
  
  OBJECTIVE
  The use of FEV(1) plus mean forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75%)) may increase the sensitivity of the ECT in asthmatic children.
  
  
  OBJECTIVE
  To compare FEV(1) and FEF(25-75%) changes in a group of asthmatic and healthy children.
  
  
  METHODS
  This was a cross-sectional study. Asthmatics were categorized by their severity (GINA) and after 1 month without controller therapy, an ECT was done under standard protocol. As well, a questionnaire about rhinitis and asthma was conducted with the entire population. ROC curves were used for analysis.
  
  
  RESULTS
  A total of 147 children (34 healthy and 113 asthmatics, 18 and 58 males, respectively) were evaluated. Divided into healthy children and intermittent, mild and moderate persistent asthmatics, they had similar average ages (9.4, 9.48, 8.97, and 11.2 years, respectively). Using a 15% fall in FEV(1), we obtained 29% sensitivity and 100% specificity. However, when we used a 10% fall in FEV(1), sensitivity was 47% and specificity was 97%. Adding a 28% fall in FEF(25-75%), sensitivity was 52% and specificity was 94%.
  
  
  CONCLUSIONS
  This study suggests that test sensitivity can increase by using a lower FEV(1) cut-off (10%) and adding a 28% fall in FEF(25-75%).
authors.affiliation: Pediatric Division, Respiratory Section, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Claudia
authors.initials: C
authors.lastname: Fuentes
authors.forename: Stefani
authors.initials: S
authors.lastname: Contreras
authors.forename: Oslando
authors.initials: O
authors.lastname: Padilla
authors.forename: Jose A
authors.initials: JA
authors.lastname: Castro-Rodriguez
authors.forename: Ana
authors.initials: A
authors.lastname: Moya
authors.forename: Solange
authors.initials: S
authors.lastname: Caussade
mesh_terms: D000293:Adolescent; D001250:Asthma, Exercise-Induced / Q000175:diagnosis*; D002648:Child; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity