In general, the reference standard was adequate. Fifty-seven patients had excisional histology. Histology available in all those in the prospective series. Studies have generally been done on subsets of patients depending upon results of clinical examination or other tests. The poor performance on this quality criterion is undoubtedly the major source of bias in all of the studies identified.
Quality is generally poorer than in studies on the triple test.
Patients were not consecutive. The study, in a German gynaecology department, included only those women who had surgery because of a suspicious clinical, ultrasound or mammographic examination. It is also unclear if the series includes abnormalities detected on screening. Women were mostly self-referred because of symptoms but women with abnormalities found on mammographic screening are also included in this study based at a clinic in Italy. Ultrasound was only done in cases showing clinical or mammographic abnormalities worthy of further assessment.