Classification of chest radiographs for epidemiological purposes by persons not experienced in the radiology of pneumoconiosis

Eight of the readers were not medically qualified. Under controlled conditions the 16 participants taught themselves to use the ILO U/C International Classification of Radiographs of Pneumoconioses.Eight experienced readers had previously classified 220 of the selected radiographs for profusion of small rounded opacities. On average, 24% had been placed into category 0, 26% into category 1, 36% into category 2, and 13% into category 3. The corresponding distributions from the self-trained readers at their third viewings of these radiographs were 12, 26, 44 and 18% for those medically qualified, and 23, 21, 38 and 18% for the eight lay readers. Variability between readers contributing to these average results was greater in the experimental panels than among the experienced readers. But the average consistency between pairs of novice readers in their use of the 12 categories of profusion for the same radiographs was similar (about 29%) to the average consistency among the experienced readers.At their first viewings of 60 radiographs of men with no occupational exposure to dust each of the 16 readers classified some of them into category 0/1 or even higher. Some continued to do so at the third readings; but with further experience the self-trained readers classified nearly all of these radiographs into category 0/0. The new readers produced plausible classifications of the radiographs for large opacities.Subsequent work with nine of the participants showed that eight of them were able to produce classifications of coalminers. chest radiographs which correlated well with estimates of the miners’ exposures to res-pirable coalmine dust. It is concluded that the ILO Classification scheme provides a sound descriptive system for recording the appearances of chest radiographs. Under controlled conditions the scheme may be used sensibly for epidemiological studies by persons with no specialist knowledge or clinical experience. This presupposes that the radiographs concerned will have been examined previously for diagnostic purposes by a suitably qualified physician. “”