On the factors influencing consistency in the radiologic diagnosis of pneumoconiosis.

The reliability and precision that experienced readers can achieve in the categorization of chest radiographs with demonstrable coal workers pneumoconiosis were investigated and quantified. An attempt was also made to assess the effect of film quality on variability of categorization. Despite the use of experienced readers, there was often a marked divergence of opinion in the assessment of both simple and complicated pneumoconiosis. Furthermore, certain observers either consistently over-read or under-read as compared with the remainder of their colleagues. In only slightly more than 50 per cent of the films was interpretation unanimous. Divergence of opinion concerning the qualities that constitute a technically satisfactory film was almost as great as that which arose from the classification of radiographs. An initial impression that the more substandard the film quality ratings given, the greater the likelihood of a disparity in diagnostic classification, was not borne out. Poor quality films had only a trivial effect on observer consistency.