title: Peak expiratory flow monitoring is not a reliable method for establishing the diagnosis of occupational asthma.
abstract: This is a study of the reliability of peak expiratory flow (PEF) monitoring using a portable computerized peak flow meter, the VMX Mini-log, in 17 subjects referred for suspected occupational asthma. Subjects were requested to monitor their PEF six times daily using the VMX Mini-Log for 2 wk at work and at least 10 d away from work. They were unaware that their readings were stored by the flow meter in addition to the digital readout. Four subjects (22%) were unable to complete the monitoring. The results recorded by the subjects were compared with the results recorded by the VMX. Of those who completed the monitoring, only 55.3% of the records were completely accurate in terms of the value and the timing of the measurements, 23.3% were inaccurate either in terms of the recorded value or of the timing of the measurement, and the remainder were fabricated results (not recorded by the Mini-Log). Our results suggest that PEF monitoring using ordinary peak flow meters for assessment of work-relatedness of asthma has limitations and is not reliable.
authors.affiliation: Department of Medicine, University of British Columbia, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Quirce
authors.forename: G
authors.initials: G
authors.lastname: Contreras
authors.forename: A
authors.initials: A
authors.lastname: Dybuncio
authors.forename: M
authors.initials: M
authors.lastname: Chan-Yeung
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009784:Occupational Diseases / Q000175:diagnosis* / Q000503:physiopathology; D010366:Peak Expiratory Flow Rate; D011237:Predictive Value of Tests; D015203:Reproducibility of Results