The Impact of the COVID-19 pandemic on attendance and diagnostic outcomes at BreastScreen Western Sydney

**Corresponding author mailto:[email protected] Background: The COVID-19 pandemic disrupted health services, including BreastScreen. This study examined BreastScreen data from 2018 to 2021 to evaluate the pandemic's effect on screening. This will inform service planning and recruitment strategies for the pandemic recovery. Methods: Data were collected for BreastScreen Western Sydney episodes between January 2018 and December 2021 including sociodemographic characteristics of clients and tumour characteristics of malignancies. Descriptive statistical analysis was performed using SPSS, to compare these characteristics in 'Pre-COVID' years (2018 and 2019) to 'COVID-affected' years (2019 and 2020). Analysis also compared data between individual years in addition to comparison by COVID grouping. Results: There were 172,977 screening episodes and 1,124 cancer diagnoses (in-situ n=216, 19.2%) during the study period. COVID-affected years demonstrated an 18.8% reduction in screening episodes (77,510 vs 95,467, p<0.001) and 16.3% reduction in malignancies (512 vs 612) compared to pre-COVID years. BreastScreen recall rate was lower during COVID-19 (4.2% vs 4.8% p<0.001). The cancer detection rate remained similar (52.3 and 52.7 per 10,000 screens). Younger women were less likely to attend BreastScreen during the COVID-affected years and there were fewer first screening rounds. There was no significant difference in the median invasive tumour size or proportion of high-grade lesions detected by BreastScreen services during the pandemic. There was no significant difference in BreastScreen attendance by clients from non-English speaking backgrounds during the pandemic (p=0.08). Conclusion: There was a reduction in the number of screens and cancers during the COVID-affected years. However, there was no difference in the characteristics of tumours or the cancer detection rate, and the recall rate was lower during the COVID-affected years. This suggests that the 'missing' (undiagnosed) cancers from the COVID-affected years should also be similar to pre-COVID. Younger women and those attending for their first screen should be targeted for catch-up screening.