Non-Medical Factors Influencing Use of Diagnostic X-ray by Physicians

The patterns of use of x-ray by physicians caring for aged persons under a medical assistance program were analyzed to determine the effect of physician characteristics on these patterns. Non-radiologists providing direct x-ray services to patients used diagnostic x-ray more frequently than did physicians referring patients to radiologists for examination, and the specialty of the physician and the number of years since his graduation from medical school were associated with significant variation in use of x-ray and choice of procedure for examination of the chest. Younger physicians used x-ray more than older ones and specialists more than general practitioners. Non-radiologists providing direct x-ray services used less complex examination procedures and, for examination of the chesty they frequently used fluoroscopy as an independent procedure. The data support the conclusion that non-radiologists having economic interest in radiologic equipment make heavier use of diagnostic x-ray than do other physicians, although their choices of examination methods suggest that their knowledge of radiology is less than that of radiologists. Patterns of use of x-ray by internists suggest a strong influence of specialty training on practice and persistence of this influence for many years. Finally, findings support national survey evidence that patients of non-radiologists providing direct x-ray services experience relatively larger exposure to radiation than do patients of other physicians.