Reproducibility of a radiographic classification of progressive massive fibrosis

In a previous report, we showed that one of us (CAS) could classify reproducibly chest radiographs showing progressive massive fibrosis (PMF) into six different types, one of which was found to be related to high quartz exposure. The same radiographs have been classified twice again by four other readers after instruction by the first, and readings for all five readers compared.

Four of the five readers classified between 72% and 77% of the radiographs identically on the two occasions; the fifth 47%. The four additional readers’ agreement with the original reader’s classifications ranged from 34% to 52% at first readings, and from 46% to 54% at the second. Agreements between each reader and the original reader at both readings were statistically highly significant for each type of PMF, including the type which was previously shown to be associated with high quartz exposure.

We have now shown that other readers can classify type of PMF consistently and similarly to the original reader. The classification may therefore be usefully applied to studies of PMF.