title: [Which definition to use when defining reversibility of airway obstruction?].
abstract: BACKGROUND
  There is no clear consensus about what constitutes reversibility of airway obstruction. European Respiratory Society (ERS): Increase in FEV1 and/or FVC>12% of their theoretical value and>0.2l. British Thoracic Society: FEV1>15% of initial value and FEV1>0.2l. Global Initiative for Chronic Obstructive Lung Disease: Increase in FEV1>12% and>0.2l. Australia and New Zealand Thoracic Society: Increase in FEV1 >15%. American Thoracic Society/ERS: Increase in FEV1>12% and>0.2l or increase in FVC>12% and 0.2l. Our principal objective was to determine the percentage of patients with COPD (n=62) who were significant responders to the reversibility test according to the 5 recommendations.
  
  
  METHODS
  Plethysmography was performed before and 15 minutes after inhalation of 400 micrograms of a short acting bronchodilator (BD). COPD is defined as a FEV1/FVC post BD<0.7.
  
  
  RESULTS
  The percentage of responders varied from 24% to 50% depending on the recommendations used.
  
  
  CONCLUSIONS
  Reversibility of airway obstruction is recommendation dependent.
authors.affiliation: Service de Physiologie et des Explorations Fonctionnelles, EPS Farhat Hached, Sousse, Tunisie. helmi.bensaad@rns.tn
authors.forename: H
authors.initials: H
authors.lastname: Ben Saad
authors.forename: R
authors.initials: R
authors.lastname: Ben Attia Saafi
authors.forename: S
authors.initials: S
authors.lastname: Rouatbi
authors.forename: S
authors.initials: S
authors.lastname: Ben Mdella
authors.forename: A
authors.initials: A
authors.lastname: Garrouche
authors.forename: A
authors.initials: A
authors.lastname: Hadj Mtir
authors.forename: I
authors.initials: I
authors.lastname: Harrabi
authors.forename: Z
authors.initials: Z
authors.lastname: Tabka
authors.forename: A
authors.initials: A
authors.lastname: Zbidi
mesh_terms: D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy*; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D001993:Bronchodilator Agents