Oral presentation

There are two competing methods for improving the accuracy of a single screening radiologist: use of a computer aid (CAD) or double reading.

Bibliographic databases were searched for studies where either intervention was incorporated into routine screening work. Meta-analyses were performed to find overall estimates of the impacts of CAD and double reading on both the cancer detection rate and the recall rate.

Ten studies were found comparing single reading with CAD to single reading. Seventeen studies were found comparing double reading to single reading. Double reading generally increases the cancer detection rate, but also the recall rate. However, double reading with arbitration increases the detection rate (95% CI = 1.02 to 1.15) and decreases the recall rate (95% CI = 0.92 to 0.96). CAD does not have a significant effect on the cancer detection rate (95% CI = 0.96 to 1.13) and increases the recall rate (95% CI = 1.09 to 1.12). However, there is considerable heterogeneity in the impact on the recall rate in both sets of studies.

There is better evidence for an improvement in the cancer detection rate with a human second reader than with CAD. Arbitration where two readers disagree also delivers a reduced recall rate, whereas CAD increases the recall rate. There are therefore strong grounds for preferring double reading with arbitration to single reading with CAD.