Reference

Cote J, Kennedy S, ChanYeung M, Quantitative Versus Qualitative Analysis Of Peak Expiratory Flow In Occupational Asthma, Thorax, 1993;48:48-51,

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 rates (PEF) are often used to confirm diagnosis of occupational asthma. Study compared the diagnostic value of a qualitative assessment of change in PEF with objective measures of change in PEF and the results of a specific inhalation challenge test with plicatic acid. 25 subjects with possible red cedar asthma recorded PEF 6 times a day for 3 weeks at work and for 2 weeks away from work and underwent a challenge test with plicatic acid at the end of the recording period. Results show that qualitative PEF analysis had sensitivity of 87% and specificity of 90% in confirming red cedar asthma as diagnosed by the specific challenge test. Authors conclude that qualitative assessment of PEF is a good diagnostic test for cedar asthma.

BOHRF Associated Evidence Statements

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

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2+

In the clinical setting questionnaires that identify symptoms of wheeze and/or shortness of breath which improve on days away from work or on holiday have a high sensitivity, but relatively low specificity for occupational asthma.

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3

Acceptable peak flow series can be obtained in around two thirds of those in whom a diagnosis of occupational asthma is being considered.

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3

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

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3

Statistical analysis of serial peak flow measurements is of limited diagnostic value compared to expert interpretation