American College of Radiology Diagnostic Efficacy Studies.

Questions about costs and benefits of radiologic diagnostic methods have lead to the formation of a standing American College of Radiology Committee on Efficacy. In the past several years this committee has defined a hierarchy of efficacies associated with radiographic procedures and developed methods for assigning a numerical value to diagnostic efficacy. A national study of common x-ray examinations in the emergency setting has been conducted. These studies suggest that diagnostic thinking of clinicians was influenced by the results of the x-ray procedures they requested in more than 92% of cases. Medicolegal consideration were a prime concern of the clinician only 6% of the time overall when selecting the most frequent radiologic procedures conducted in hospitals. Considerable uncertainty about clinical diagnoses was typically present at the time radiologic examinations were requested; three-fourths of the time the most important diagnosis under consideration was judged to be less likely after x-ray examination than before. About one-eighth of the time the radiographic information focused attention on a new "most important" diagnosis. The committee plans further studies to include other imaging modalities and practive settings.