International classification trial of AIA set of 100 radiographs of asbestos workers

Our plain-English summary of International classification trial of AIA set of 100 radiographs of asbestos workers, by C.E. Rossiter, K. Browne, J.C. Gilson (British Journal of Industrial Medicine, 1988).

The study

• Authors: C.E. Rossiter, K. Browne, J.C. Gilson
• Journal: British Journal of Industrial Medicine
• Published: 1988;45(8):538-43
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000932).

Abstract

A series of 100 full size radiographs illustrating the range of asbestos related radiographic changes was collected by the Asbestos International Association to provide a demonstration and teaching supplement to the ILO 1980 International Classification of the Radiographic Appearances of Pneumoconioses. Each film was read by 12 experienced readers from ten countries; the readings have been summarised by a median reading, with the range covered by two thirds of the readers. The occupational histories and some relevant clinical information are also available. It is proposed that, in the use of this set, readers should classify each film using the ILO classification rules, particularly without reference to the summary reading or the additional information. Comparing the individual readings by the 12 readers, most of the variation in reading the profusion of small opacities was ascribable only to random variation, with little consistent bias between readers. By contrast, two readers recorded pleural changes much more frequently than their colleagues. This illustrated a major problem with the ILO 1980 Classification. Several others which occurred in this reading trial are also discussed.

In plain English

This article reported an international reading trial of a teaching set of chest X-rays of asbestos workers. The Asbestos International Association assembled the set to supplement the ILO 1980 International Classification of the Radiographic Appearances of Pneumoconioses. About 200 films were collected from nine countries, from workers in mining, asbestos cement, friction materials, insulation board, textiles and thermal insulation. The final set had 100 films. Twelve experienced readers from 10 countries each classified every film, and the middle (median) reading was taken as the best estimate for each film. For small opacities in the lung tissue, the authors judged that differences between readers were not large compared with general variability in reading. Even so, the share of films each reader placed at subcategory 2/1 or more ranged from 16% to 38%. Pleural changes were recorded far less consistently. One reader recorded pleural thickening on all but four films, and another read 78 films as positive, compared with 38 to 60 for the other ten readers. The authors concluded that this part of the classification needs improvement.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: International reading trial comparing how 12 readers classified the same chest radiographs using the ILO 1980 Classification; the readings were summarised by a median reading for each film
• Who was studied: About 200 radiographs of asbestos workers were collected from nine countries (Australia, Belgium, Denmark, France, Italy, Japan, Saudi Arabia, the Republic of South Africa and the United Kingdom). 102 were selected and 100 remained in the final set. Twelve readers from 10 countries read the films; the first subset of 25 films was read between April and June 1983.
• Exposure: Employment in asbestos mining; in the manufacture of asbestos cement, friction materials, insulation board and textiles; and in the thermal insulation industry. Fiber types and doses were not given.
• Main results:
  • By median reading, 84 films were positive for small opacities. All but four of these were recorded as irregular in shape.
  • For profusion of small opacities, the authors' overall impression was that differences between readers were not large compared with variability in reading.
  • Across readers, the proportion of films recorded as subcategory 2/1 or more ranged from 16% to 38%.
  • The proportion of each reader's readings that were more than one subcategory from the median ranged from 13% to 32%.
  • Of the 18 films with the greatest reading discrepancies, 13 (72%) were recorded as film quality 1. This did not differ significantly from the 79% for the whole set.
  • Median readings of pleural thickening were positive on both sides for 33 films, on one side for 19 films, and negative for 48 films.
  • Reader 6 recorded pleural thickening on all but four films. Reader 11 read 78 films as positive, compared with a range of 38 to 60 for the remaining ten readers.
  • Median readings were positive for pleural calcification on 18 films, nine of them on both sides. Readers 6 and 11 read pleural calcification on 29 and 27 films respectively, against a range of 14 to 25 for the other readers.
• The authors' conclusion: The authors concluded that the trial confirmed wide variation in how readers record pleural changes, and that this part of the ILO Classification needs to be improved. They also stated that, without improved standardisation, the classification cannot fulfil its purposes.
• Limitations the authors state:
  • The authors noted that their definition of the median reading led to a slight bias towards abnormality.

Topics

Medical terms in this study, explained in our Lexicon: ILO Classification.

Related studies

• Relationships (I) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with the ILO International Classification of Radiographs of Pneumoconioses for parenchymal abnormalities — T. Tamura, N. Suganuma, et al. (2015)
• Risk and significance of chest radiograph and pulmonary function abnormalities in an elderly cohort of former nuclear weapons workers — M.A. Mikulski, P.G. Hartley, et al. (2011)
• Radiological and pathological correlations in asbestosis in the Republic of South Africa and the United Kingdom. II. A preliminary study of observer variation in the classification of radiographs of asbestos-exposed workers and the relation of pathology and x-ray appearances — A. Caplan, J.C. Gilson, et al. (1965)
• Long term radiological effects of short term exposure to amosite asbestos among factory workers — R. Ehrlich, R. Lilis, et al. (1992)
• Comparison of independent randomised reading of radiographs with direct progression scoring for assessing change in asbestos-related pulmonary and pleural lesions — G.H. McMillan, C.E. Rossiter, et al. (1982)
• Changes on radiographs of wives of workers exposed to asbestos — L. Sider, E.A. Holland, et al. (1987)

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