Reliability and validity of chest radiograph surveillance programs

Study objectives: Due to the lack of consensus in the literature in the use of postcroanterior (PA) vs PA with right and left oblique views as the opt imum radiograph surveillance methodology to investigate pleural changes, a study was undertaken to evaluate the reliability, sensitivity, and specific ity of these two approaches. Design: Three experienced radiologist B readers used the 1980 international Labor Office classification system for pneumoconiosis to independently rea d chest radiographs of workers with individual identifiers masked. All radi ographs were read first as a PA view only. Unknown to the B readers, each s ubject's PA was then matched to his or her corresponding right and left obl ique views (film triad) and re-read several weeks later. Setting and partic ipants: The respiratory health of 652 workers exposed to refractory ceramic fiber was assessed as part of cross-sectional and longitudinal surveillanc e programs. Measurements and results: K Statistics for interreader and intrareader reli ability between the PA view and film triad methods were calculated. Sensiti vity, specificity, and positive predictive value were assessed by comparing the initial cross-sectional study to the longitudinal study, The film tria d method had considerably higher interreader reliability (kappa = 0.59) com pared to the PA-only method (kappa = 0.44), Results from the initial cross- sectional study cr ere then compared to findings evaluated longitudinally, The film triad again was superior, demonstrating a positive predictive valu e of 73.7% compared to only 47.8% for the PA method. Conclusions: It is our recommendation that the film triad method be used in surveillance studies where both parenchymal and pleural changes are antici pated,