Journal of Allergy and Clinical Immunology
Compliance with peak expiratory flow readings affects the within- and between-reader reproducibility of interpretation of graphs in subjects investigated for occupational asthma☆,☆☆,★,★★
Section snippets
Subjects
The 34 subjects included in this study were previously described. This includes 13 subjects investigated at the Vancouver General Hospital3 and 21 investigated at Sacré-Coeur Hospital.4 There were 31 men and 3 women, and their mean age was 39 (± 12 SD) years. There were 22 atopic subjects (defined by the presence of at least one immediate reaction to a battery of 15 inhalant allergens as determined by the prick method). The mean duration of exposure at work was 14 (± 11 SD) years, and the mean
RESULTS
The within-reader concordance of written and stored values is shown in Table I. The concordance of readings was not very satisfactory according to the kappa values. For example, for Reader no. 1, the calculation for kappa statistics according to the Appendix is as follows: Proportion of observed agreement = (26 + 3) ÷ 34 = 0.85; Proportion of expected agreement = [27 ÷ 34 × 30 ÷ 34] + [4 ÷ 34 × 7 ÷ 34] = 0.72); Kappa value = ([0.85 – 0.72)] ÷ [1.0 – 0.72]) = 0.47. Kappa values were slightly
DISCUSSION
Studies have shown that compliance with PEF recording is not satisfactory in the investigation of OA.3, 4 This study shows that this affects the within-subject reproducibility of readings in a significant way. The kappa values for comparison of the self-reported and stored values varied from 0.47 to 0.61 according to the three readers. The within-reader reproducibility of readings was shown to be much higher (kappa values varying from 0.91 to 1.0 for readings at 2-hour intervals) in a previous
Acknowledgements
We thank Lori Schubert for reviewing the manuscript.
References (5)
- et al.
Do subjects investigated for occupational asthma through serial peak expiratory flow measurements falsify their results?
J Allergy Clin Immunol
(1995) Physiologic assessment of occupational asthma
Cited by (0)
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From athe Department of Chest Medicine, Sacré-Coeur Hospital, Montreal, Canada; and bthe Department of Medicine, Vancouver General Hospital.
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Supported in part by the Centre Québécois d’Excellence en Santé Respiratoire. Members of the Canadian Network of Centers of Excellence. Dr. Malo is a research scholar with the Fonds de la Recherche en Santé du Québec.
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Reprint requests: Jean-Luc Malo, MD, Department of Chest Medicine, Sacré-Coeur Hospital, 5400 West Gouin, Montreal, Quebec, Canada H4J 1C5.
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0091-6749/96 $5.00 + 0 1/54/77594