A comparison of breast screening performance based on a standardised test, during and outside of the COVID-19 lockdown period

Purpose: In the UK, the COVID-19 pandemic and the resulting lockdown significantly impacted routine breast screening and led to reduced case volumes for breast screening readers. The aim of the study was to evaluate whether breast screening performance on a test-set based assessment scheme (PERFORMS) varied over time, in association with the lockdown period.Method: In this retrospective study, performance data were obtained for all breast cancer screening readers in England who completed the PERFORMS schemes based on digital mammography (from 2015 to 2022). Cancer detection (sensitivity), correct return to screen (specificity) and the difference between the sensitivity and specificity were calculated for each breast screener in each PERFORMS scheme.Results: During the study period, 4906 readers participated in eight PERFORMS schemes. Both the cancer detection (H(7) = 775.56, p <.00001) and correct return to screen rate (H(7) = 401.13, p <.00001) varied significantly by scheme. The difference between cancer detection and correct return to screen rate in the scheme administered during the lockdown period was significantly higher than in all other schemes (p <.05, Bonferroni correction applied). Conclusions: The performance of breast screeners on the PERFORMS test-set based assessment scheme which was administered during the lockdown period, was characterised by markedly high sensitivity and low specificity when compared to their performance on other tests taken pre-COVID and following the lockdown.