Development of an expert system for the interpretation of serial peak expiratory flow measurements in the diagnosis of occupational asthma. Midlands Thoracic Society Research Group.

If asthma is due to work exposures there must be a relation between these exposures and the asthma. Asthma causes airway hyperresponsiveness and obstruction; the obstruction can be measured with portable meters, which usually measure peak expiratory flow, or sometimes forced expiratory volume in 1 second (FEV1). These can be measured serially (for instance 2 hourly) over several weeks at and away from work. Once occupational asthma develops, the asthma will be induced by many non-specific triggers common to non-occupational asthma. The challenge is to identify changes in peak expiratory flow due to work among other non-occupational causes. Standard statistical tests have been found to be insensitive or non-specific, principally because of the variable period for deterioration to occur after exposure, and the sometimes prolonged time for recovery to occur, such that days away from work may initially have lower measurements than days at work. A computer assisted diagnostic aid (Oasys) has been developed to separate occupational from non-occupational causes of airflow obstruction. Oasys-2 is based on a discriminant analysis, and achieved a sensitivity of 75% and a specificity of at least 94%; therefore peak expiratory flow monitoring combined with Oasys-2 analysis is better to confirm than to exclude occupational asthma. A neural network version in development has improved on this. Both have been based on expert interpretation of peak flow measurements plotted as daily maximum, mean, and minimum, with the first reading at work taken as the first reading of the day. Oasys has been evaluated with independent criteria against measurements made in a wide range of occupational situations. Oasys is sufficiently developed to be the initial method for the confirmation, although less so for exclusion of occupational asthma.

[1]  P. Burge,et al.  The effect of patient technique and training on the accuracy of self-recorded peak expiratory flow. , 1999, The European respiratory journal.

[2]  P. Burge,et al.  Effect of the number of peak expiratory flow readings per day on the estimation of diurnal variation , 1998, Thorax.

[3]  M. Chan-yeung,et al.  Compliance with peak expiratory flow readings affects the within- and between-reader reproducibility of interpretation of graphs in subjects investigated for occupational asthma. , 1996, The Journal of allergy and clinical immunology.

[4]  P. Burge,et al.  The diagnosis of occupational asthma from serial measurements of lung function at and away from work , 2022 .

[5]  P. Burge,et al.  Development of OASYS-2: a system for the analysis of serial measurement of peak expiratory flow in workers with suspected occupational asthma. , 1996, Thorax.

[6]  J. Malo,et al.  Do subjects investigated for occupational asthma through serial peak expiratory flow measurements falsify their results? , 1995, The Journal of allergy and clinical immunology.

[7]  J. Malo,et al.  Statement on self-monitoring of peak expiratory flows in the investigation of occupational asthma. Subcommittee on Occupational Allergy of the European Academy of Allergology and Clinical Immunology. American Academy of Allergy and Clinical Immunology. European Respiratory Society. American College , 1995, The European respiratory journal.

[8]  L. Boulet,et al.  How many times per day should peak expiratory flow rates be assessed when investigating occupational asthma? , 1993, Thorax.

[9]  D J Hitchings,et al.  The accuracy of portable peak flow meters. , 1992, Thorax.

[10]  V. Søyseth,et al.  Serial measurements of peak expiratory flow and responsiveness to methacholine in the diagnosis of aluminium potroom asthma. , 1992, Thorax.

[11]  L. Boulet,et al.  Occupational asthma: validity of monitoring of peak expiratory flow rates and non-allergic bronchial responsiveness as compared to specific inhalation challenge. , 1992, The European respiratory journal.

[12]  G. Liss,et al.  Peak expiratory flow rates in possible occupational asthma. , 1991, Chest.

[13]  M. Chan-yeung,et al.  Sensitivity and specificity of PC20 and peak expiratory flow rate in cedar asthma. , 1990, The Journal of allergy and clinical immunology.

[14]  J. Malo,et al.  Guidelines for bronchoprovocation on the investigation of occupational asthma. Report of the Subcommittee on Bronchoprovocation for Occupational Asthma. , 1989, The Journal of allergy and clinical immunology.

[15]  P. Burge,et al.  Peak flow rate records in surveys: reproducibility of observers' reports. , 1984, Thorax.

[16]  T J Clark,et al.  Comparison of normal and asthmatic circadian rhythms in peak expiratory flow rate. , 1980, Thorax.

[17]  P. Burge,et al.  Bronchial provocation studies in workers exposed to the fumes of electronic soldering fluxes , 1980, Clinical allergy.

[18]  P. Burge,et al.  Peak flow rate records in the diagnosis of occupational asthma due to colophony. , 1979, Thorax.

[19]  P. Burge,et al.  Peak flow rate records in the diagnosis of occupational asthma due to isocyanates. , 1979, Thorax.

[20]  B M WRIGHT,et al.  Maximum Forced Expiratory Flow Rate as a Measure of Ventilatory Capacity , 1959, British medical journal.

[21]  G. Harley.  On the Capacity of the Lungs, and on the Respiratory Functions , 1856, The British and foreign medico-chirurgical review.

[22]  P. Burge.  Problems in the diagnosis of occupational asthma. , 1987, British journal of diseases of the chest.

[23]  P. Burge,et al.  Single and serial measurements of lung function in the diagnosis of occupational asthma. , 1982, European journal of respiratory diseases. Supplement.

[24]  Burge Ps.  Single and serial measurements of lung function in the diagnosis of occupational asthma. , 1982 .

[25]  M. Turner‐Warwick.  On observing patterns of airflow obstruction in chronic asthma. , 1977, British journal of diseases of the chest.

[26]  J Hutchinson,et al.  On the capacity of the lungs, and on the respiratory functions, with a view of establishing a precise and easy method of detecting disease by the spirometer. , 1846, Medico-chirurgical transactions.