**5. Conclusions**

The mammographic breast density increases recall rates and biopsy recommendations, and women with dense breasts recalled for assessment are more likely to have a false-positive biopsy compared to those with fatty breasts. In dense breasts, ultrasound showed greater potential to decrease unnecessary biopsies than DBT, with every benign lesion in dense breasts being unnecessarily recalled having approximately a 50% chance of benefiting from ultrasound. DBT and ultrasound perform comparatively similar in reducing unnecessary benign biopsies in fatty breasts. Therefore, tailoring assessment pathways according to breast density may reduce unnecessary biopsies and anxiety in women recalled for assessment.

**Author Contributions:** Conceptualization, I.H., M.M. and E.E.; methodology, I.H. and E.E.; validation, I.H., E.E., M.M., J.C., W.R. and W.V.; analysis, I.H.; investigation, I.H. and E.E.; data collection, I.H.; writing—original draft preparation, I.H.; writing—review and editing, I.H., E.E., M.M., J.C., W.R. and W.V.; supervision, E.E. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** The study was conducted in accordance with the Declaration of Helsinki, and received ethics approval from the New South Wales health department (IRB: X19-0495) and local approval from Sydney Local Health District (2019/ETH13792), date of approval: 11 February 2020.

**Informed Consent Statement:** The Committee granted a waiver of the usual requirement for the consent of the individual for the use of their health information in a research project, in accordance with the Health Records and Information Privacy Act 2002 (NSW) and the NSW Privacy Commissioner's Statutory guidelines on research and the NHMRC Guidelines approved under Section 95A of the Privacy Act 1988.

**Data Availability Statement:** Data are available from the authors with the permission of BreastScreen NSW, Sydney Local Health District.

**Acknowledgments:** We want to thank Beby Thung Winata for assisting with data collection.

**Conflicts of Interest:** The authors declare no conflict of interest.
