Rml. Warren et Sw. Duffy, COMPARISON OF SINGLE READING WITH DOUBLE READING OF MAMMOGRAMS, AND CHANGE IN EFFECTIVENESS WITH EXPERIENCE, British journal of radiology, 68(813), 1995, pp. 958-962
In the prevalence round of screening for breast cancer at a single cen
tre, the benefit of the second radiological report has been assessed u
sing data from 33 734 women, their screening results and knowledge of
the interval cancers. The service was set up under the UK National Bre
ast Screening Programme, and the data show evidence of learning by bot
h individuals and the team as a whole. Of the 269 cancers detected by
screening 33 would not have been diagnosed if the only report availabl
e had been the first. The recall recommendation rate associated with t
he first report was 6.9% and 236 cancers were detected. The recall rec
ommendation rate associated with all queries of all the reports was 10
% (3354 queries). Had these 3354 queries all been investigated (instea
d of the 1423 actually recalled) only a further three cancers would ha
ve been detected. Sensitivity of the programme as a whole was substant
ially better than that of individual radiologists, while the specifici
ty was maintained. The decision pathway by which recalls were agreed b
etween the two radiologists resulted in a low recall rate (4.2%) for t
he programme as a whole, and is a critical factor in gaining the benef
it of the improved sensitivity without a concomitant deterioration in
the specificity. With the passage through the prevalent round, recall
rates steadily fell, the malignant to benign biopsy ratio improved and
sensitivity increased. The second radiological report yielded 14% add
itional cancers diagnosed and contributed very significantly to good s
ensitivity and so to the effectiveness of screening. Economic analysis
of the results will be reported in a further paper.