A sequential chart for the audit-based evaluation of screening mammogram interpretation

Rationale and Objectives, Auditing has received much attention recently as a method for radiologists to use to evaluate their interpretation of screen ing mammograms, U.S. Food and Drug Administration regulations require that some sort of audit be in place before a mammography screening facility can receive accreditation. Auditing presents a unique opportunity to monitor ac curacy continually and identify problems early. Audit data present unique c hallenges, however, and appropriate methods must be used to control the ris k of errors. Materials and Methods. This article introduces a simple method for the task of deciding if a radiologist yields an acceptable positive predictive valu e based on audit. The method is based on "sequential" decision-making techn iques that have found wide application in quality control problems. These t echniques are developed for diagnostic radiology and embodied in an easy-to -use decision-making chart. Results. Several examples, based on audit data from actual mammography faci lities, provide insights into the use of these charts and the influence of (a) the selection of standards, (b) the selection of error risks, and (c) r adiologist variability. The tramples also serve to demonstrate another impo rtant property of this method-that is, it specifies the minimum amount of d ata that has to be collected before any decision can reliably be made. Conclusion. The chart presented in this article provides a method by which audit data can be used objectively to evaluate the accuracy of screening ma mmogram interpretation. The method controls the risk of either falsely acce pting an unqualified radiologist or falsely rejecting a qualified radiologi st, It should be a useful tool to radiologists who must evaluate their own practices.