title: Worldwide patterns of bronchodilator responsiveness: results from the Burden of Obstructive Lung Disease study.
abstract: BACKGROUND
  Criteria for a clinically significant bronchodilator response (BDR) are mainly based on studies in patients with obstructive lung diseases. Little is known about the BDR in healthy general populations, and even less about the worldwide patterns.
  
  
  METHODS
  10 360 adults aged 40 years and older from 14 countries in North America, Europe, Africa and Asia participated in the Burden of Obstructive Lung Disease study. Spirometry was used before and after an inhaled bronchodilator to determine the distribution of the BDR in population-based samples of healthy non-smokers and individuals with airflow obstruction.
  
  
  RESULTS
  In 3922 healthy never smokers, the weighted pooled estimate of the 95th percentiles (95% CI) for bronchodilator response were 284 ml (263 to 305) absolute change in forced expiratory volume in 1 s from baseline (ΔFEV(1)); 12.0% (11.2% to 12.8%) change relative to initial value (%ΔFEV(1i)); and 10.0% (9.5% to 10.5%) change relative to predicted value (%ΔFEV(1p)). The corresponding mean changes in forced vital capacity (FVC) were 322 ml (271 to 373) absolute change from baseline (ΔFVC); 10.5% (8.9% to 12.0%) change relative to initial value (ΔFVC(i)); and 9.2% (7.9% to 10.5%) change relative to predicted value (ΔFVC(p)). The proportion who exceeded the above threshold values in the subgroup with spirometrically defined Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 2 and higher (FEV(1)/FVC <0.7 and FEV(1)% predicted <80%) were 11.1%, 30.8% and 12.9% respectively for the FEV(1)-based thresholds and 22.6%, 28.6% and 22.1% respectively for the FVC-based thresholds.
  
  
  CONCLUSIONS
  The results provide reference values for bronchodilator responses worldwide that confirm guideline estimates for a clinically significant level of BDR in bronchodilator testing.
authors.affiliation: University of British Columbia, UBC iCapture Centre for CardioPulmonary Research, St Paul's Hospital, 1081 Burrard Street, Vancouver, BC, Canada. wan.tan@hli.ubc.ca
authors.forename: Wan C
authors.initials: WC
authors.lastname: Tan
authors.forename: William M
authors.initials: WM
authors.lastname: Vollmer
authors.forename: Bernd
authors.initials: B
authors.lastname: Lamprecht
authors.forename: David M
authors.initials: DM
authors.lastname: Mannino
authors.forename: Anamika
authors.initials: A
authors.lastname: Jithoo
authors.forename: Ewa
authors.initials: E
authors.lastname: Nizankowska-Mogilnicka
authors.forename: Filip
authors.initials: F
authors.lastname: Mejza
authors.forename: Thorarinn
authors.initials: T
authors.lastname: Gislason
authors.forename: Peter G J
authors.initials: PG
authors.lastname: Burney
authors.forename: A Sonia
authors.initials: AS
authors.lastname: Buist
mesh_terms: D000328:Adult; D000368:Aged; D001993:Bronchodilator Agents / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects* / Q000502:physiology; D014943:Global Health; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D012016:Reference Values; D012720:Severity of Illness Index; D013147:Spirometry / Q000379:methods; D014797:Vital Capacity / Q000187:drug effects* / Q000502:physiology
chemical_list: D001993:Bronchodilator Agents