Reference

Malo JL, Cote J, Cartier A, Boulet LP, L'Archeveque J, ChanYeung M, How Many Times Per Day Should Peak Expiratory Flow Rates Be Assessed When Investigating Occupational Asthma?, Thorax, 1993;48:1211-1217,

BOHRF Original Authors' Main Conclusions

The original authors' main conclusions are taken from Abstract, Results and Discussion. They are decided upon by the authors of the BOHRF occupational asthma guidelines and form part of the guidelines.

Peak expiratory flow (PEF) rate recording was carried out in 74 subjects referred for possible occupational asthma, to determine the optimum number of recordings required per day to determine the best between-reader and within- reader reproducibility and sensitivity to specificity ratio. Specific inhalation challenges performed in a hospital laboratory or at the workplace (positive in 33 subjects and negative in 41) were considered the gold standard. Graphs of PEF recordings were generated in 4 different ways: every 4 hours, 4 times/day, 3 times/day, and every morning and evening and were assessed blindly by 3 readers in 3 different centres. Recording PEF every 2 hours results in a slightly more satisfactory agreement between readers and in concordance in terms of sensitivity/specificity than less frequent readings (4 times/day assessment almost as satisfactory).

The following comments are from the editors of the BOHRF occupational asthma guidelines and form part of the guidelines.

Almost all low molecular weight agents

BOHRF Associated Evidence Statements

The BOHRF occupational asthma guidelines state that this reference is associated with the following evidence statements

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3

The diagnostic performance of serial peak flow measurements falls when fewer than four readings a day are made.

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3

There is high level of agreement between expert interpretations of serial peak flow records.

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3

The sensitivity and specificity of serial peak flow measurements are high in the diagnosis of occupational asthma