Interrogating expert observer performance in a BreastScreen Australia radiology cohort

Breast cancer has the highest incidence among Australian women, with approximately 20,000 new cases diagnosed in 2022. The national screening program, BreastScreen Australia (BSA), plays a crucial role in early detection, which significantly improves survival rates. Using data from 592 readers on the BreastScreen Reader Assessment Strategy (BREAST) platform collected between 2014-2024, this study evaluated the differences in clinical workload and demographic characteristics between BSA readers performing at or above the 95^th percentile, compared to that of the general cohort. Furthermore, the impact of cases per week on sensitivity, specificity, lesion localization accuracy, ROC AUC, and JAFROC was considered. It was found that top performing readers had significantly more years in their clinical roles, read more cases per week, and had more experience in mammogram reading. An increased number of cases per week (CPW) was significantly associated with better performance, with a performance plateau observed at approximately 101-150 cases per week. These insights highlight the importance of maintaining reader caseload to achieve optimal screening performance and may inform future guidelines for reader benchmarks and training in the BSA program.