Methods of Assessing Serial Films of the Pneumoconioses: a Review

This is a review of all known studies of methods of readingserial postero-anterior chest X-rays to obtain measures of changefrom one film to the next. Only those trials reported since1965 are relevant: in 7 of them (involving some 17 readers anda total of nearly 4000 films) reading side-by-side in knownchronological sequence was compared with independent randomizedreading. In side-by-side reading, disguise of temporal orderhas been attempted, and various methods of assessing changehave been tried. Other relevant information is discussed. Onthe evidence from British and Canadian sources, side-by-sidereading is the method of choice, although how to record changewill depend on the objective. The American evidence indicateslittle difference between methods, but side-by-side readingis still preferred if only because of its relative simplicity. Professor F. D. K. Liddell, Department of Epidemiology and Health, McGill University, 3775 University Street, Montreal, Quebec, Canada H3A 2B4.