A private breast imaging practice: medical audit of 25,788 screening and 1,077 diagnostic examinations.

During 1989 and 1990, 25,788 screening and 1,077 diagnostic breast imaging examinations were performed. Audit was performed in 6-month intervals to allow comparison of performance over time. Sensitivity, positive predictive value, and stage of disease were determined for each radiologist, for patients over and those under 50 years of age, and for patients with and for those without a suspect palpable breast abnormality. In the screening portion of the study, 1,539 of 25,788 (5.9%) patients were asked to return for diagnostic breast imaging, 119 of 188 (63%) cancers were stage 0 or stage 1 disease, and a sensitivity of 91% and a positive predictive value of 11% were found. If patients with a palpable breast abnormality were eliminated, 103 of 138 (75%) patients had disease that was less than stage 2. In the diagnostic portion of the study, 296 of 1,077 (27%) patients were referred for biopsy and 53 of 71 (75%) cancers were stage 0 or stage 1 disease. A sensitivity of 97% and a positive predictive value of 24% were found. If patients with a palpable breast abnormality were eliminated, 51 of 63 (81%) patients had disease that was less than stage 2.