THE IMPACT OF CLINICAL HISTORY ON MAMMOGRAPHIC INTERPRETATIONS

Objective.-To determine whether mammographic interpretations are biase d by the patient's clinical history. Design.-On 2 occasions, separated by a 5-month wash-out period, 10 radiologists read mammograms for the same 100 women, randomly divided into 2 groups of 50. For 1 group, th e clinical history was supplied for the first reading and omitted (exc ept for age) for the second reading. This sequence was reversed in the other group, In addition, 5 cases were shown a third time with a deli berately leading sham history, Patients.-Selected with stratified rand om sampling from 3 categories of diagnostic findings (64 had mammograp hic abnormalities) and from the definitive designation of breast cance r or no breast cancer (18 had breast cancer). Main Outcome Measures.-R adiologists' diagnostic accuracy and directional changes in interpreta tions and recommendations between the 2 readings. Results.-The directi on suggested by the history led to small but consistent changes in the interpretations. Overall diagnostic accuracy was not altered, but rec ommendations were affected for appropriate further diagnostic workup: an alerting history leg, breast symptoms or family history of breast c ancer) increased the number of workups recommended in patients without cancer (P=.01); and a nonalerting history led to fewer recommended wo rkups in the cancer patients (P=.02), The direction of the sham histor ies led an average of 4 of the 10 radiologists to change previous diag noses and an average of 1 radiologist to change a previous biopsy reco mmendation. Conclusions.-Knowledge of the clinical history may alter a radiologist's level of diagnostic suspicion without improving perform ance in either diagnosis or management recommendations.