A comparison of Australian and USA radiologists' performance in detection of breast cancer

The aim of current work was to compare the performance of radiologists that read a higher number of cases to those that read a lower number, as well as examine the effect of number of years of experience on performance. This study compares Australian and USA radiologist with differing levels of experience when reading mammograms. Thirty mammographic cases were presented to 41 radiologists, 21 from Australia and 20 from the USA. Readers were asked to locate and visualize cancer and assign a mark-rating pair with confidence levels from 1 to 5. A jackknife free-response receiver operating characteristic (JAFROC), inferred receiver operating characteristic (ROC), sensitivity, specificity and location sensitivity were calculated. A Mann-Whitney test was used to compare the performance of Australian and USA radiologists using SPSS software. The results showed that the USA radiologists sampled had more years of experience (p0.01) but read less mammograms per year (p0.03). Significantly higher sensitivity and location sensitivity (p 0.001) were found for the Australia radiologists when experience and the number of mammograms read per year were taken into account. There were no differences between the two countries in overall performance measured by JAFROC and inferred ROC. For the most experienced radiologists within the Australian sample experienced ROC and location sensitivity were higher when compared to the least experienced. The increased number of years experience of the USA radiologists did not result in an increase in any performance metrics. The number of cases per year is a better predictor of improved diagnostic performance.