title: Can a normal peak expiratory flow exclude severe chronic obstructive pulmonary disease?
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is underdiagnosed. One barrier to diagnosis is the limited availability of spirometry testing, but in adults at risk for COPD, a normal pre-bronchodilator (pre-BD) peak expiratory flow (PEF) may rule out clinically significant COPD.
  
  
  OBJECTIVE
  To identify post-BD airway obstruction using data from 13 708 individuals aged >or=40 years from the PLATINO and BOLD studies.
  
  
  METHODS
  We evaluated different cut-off points of pre-BD. The PEF was obtained from a diagnostic-quality spirometer (not a mechanical PEF meter). At least one of the following COPD risk factors was present in 77% of the subjects: chronic respiratory symptoms; exposure to tobacco smoke, biomass smoke or dust in the workplace; or a previous diagnosis of asthma, COPD, emphysema or chronic bronchitis.
  
  
  RESULTS
  Although the positive predictive value was low as expected, a pre-BD PEF of >or=70% predicted effectively ruled out Stages III and IV COPD of the Global Initiative for Chronic Obstructive Lung Disease. Among those with at least one risk factor, only 12% would require confirmatory spirometry using this criterion.
  
  
  CONCLUSIONS
  Adding PEF measurement to a screening questionnaire may rule out severe to very severe COPD without the need for pre- and post-BD spirometry testing. Confirmation is needed from a study using inexpensive PEF meters or pocket spirometers with a staged screening protocol.
authors.affiliation: Instituto Nacional de Enfermedades Respiratorias, Mexico DF, Mexico. perezpad@servidor.unam.mx
authors.forename: R
authors.initials: R
authors.lastname: Perez-Padilla
authors.forename: W M
authors.initials: WM
authors.lastname: Vollmer
authors.forename: J C
authors.initials: JC
authors.lastname: Vázquez-García
authors.forename: P L
authors.initials: PL
authors.lastname: Enright
authors.forename: A M B
authors.initials: AM
authors.lastname: Menezes
authors.forename: A S
authors.initials: AS
authors.lastname: Buist
mesh_terms: D000368:Aged; D000402:Airway Obstruction / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000188:drug therapy; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000706:statistics & numerical data
chemical_list: D001993:Bronchodilator Agents