The influence of clinical information on the accuracy of diagnostic mammography.

OBJECTIVE: This study examined the influence of knowledge of clinical information on the accuracy of mammography in women referred for investigation of breast symptoms. METHODS: Subjects were sampled from all women consecutively attending a symptomatic breast clinic and aged 25-55 years. This included all 240 women shown to have breast cancer and 240 age-matched women shown not to have cancer. Mammography films were prospectively reported by two radiologists independently of each other in a blinded manner and without knowledge of any clinical information. The films were then re-read with information about the type and site of symptoms (and without knowledge of the level of suspicion of cancer on clinical examination). The accuracy of reading with and without information on symptoms was compared using sensitivity and specificity and receiver operating characteristic (ROC) curves. The effect of age on changes in test accuracy was examined. RESULTS: Reporting the mammogram with knowledge of clinical information (compared to without any information) significantly improved sensitivity (75.8 vs. 71.3%, P = 0.003) for one radiologist, with a non-significant reduction in specificity (85.4 vs. 87.1%, P = 0.22). For the other radiologist, it resulted in non-significant improvement in both sensitivity (75.4 vs. 73.8%, P = 0.13) and specificity (89.2 vs. 87.9%, P = 0.25). Age did not have a statistically significant effect on changes in test accuracy in our data. ROC curves for both radiologists showed that reporting mammography with knowledge of clinical information resulted in small (about 2%) but significant improvement in overall test accuracy. CONCLUSION: Our findings support the provision of clinical information relating to patients' presentation to radiologists reporting diagnostic mammography.