Can a normal peak expiratory flow exclude severe chronic obstructive pulmonary disease?
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.
Perez-Padilla
R
R
Instituto Nacional de Enfermedades Respiratorias, Mexico DF, Mexico. perezpad@servidor.unam.mx
Vollmer
W M
WM
Vázquez-García
J C
JC
Enright
P L
PL
Menezes
A M B
AM
Buist
A S
AS
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
D001993:Bronchodilator Agents