Background: In the last decade, there has been an unprecedented amount of advocacy and attention surrounding the issue of breast density (BD) in relation to mammography screening. It is largely unknown what impact notifying women of their BD has had on clinical practice for PCPs. This systematic review aimed to synthesize evidence from existing studies to understand the impact of BD notification on primary care practitioners' (PCPs) knowledge, attitudes, and practice implications. Methods: Empirical studies were identified through relevant database searches (database inception to May 2020). Two authors evaluated the eligibility of studies, extracted and crosschecked data, and assessed the risk of bias. Results were synthesized in a narrative form. Results: Six studies of the 232 titles identified and screened were included. All studies were undertaken in the United States, with five conducted postlegislation in their respective states, and one study conducted in states that were both prelegislation and postlegislation. Five studies were quantitative, including four cross-sectional surveys, and one study was qualitative. Findings consistently demonstrated PCPs' overall lack of knowledge about BD, low level of comfort in discussing and managing patients in relation to dense breasts, and limited consensus on the most appropriate approach for managing women with dense breasts, particularly in relation to supplemental screening. Conclusions: This review highlights important gaps in PCPs' understanding of BD and confidence in having discussions with women about the implications of dense breasts. It identifies the need for high-quality research and the development of evidence-based guidelines to better support PCPs.
Keywords: breast density; legislation; mammography; notification; primary care; systematic review.