Factors associated with women's supplemental screening intentions following dense breast notification in an online randomised experimental study

Controversy surrounding recommendations for supplemental screening (ultrasound and magnetic resonance screening) in women with dense breasts exists, as the long-term benefits from these additional modalities may not outweigh the harms. This study aimed to examine factors associated with supplemental screening intentions following a hypothetical breast density notification in a population of women who have not been routinely notified. Australian women of breast screening age participated in an online randomised experimental study where they were presented with one of two breast density notifications (with or without health literacy-sensitive information) and asked their screening intentions. After adjusting for covariates in multivariable analyses, women in both groups (n=940) who indicated higher levels of breast cancer worry, had private health insurance, had a family history of breast cancer, and had a greater number of times previously attending mammography screening had higher intentions for supplemental screening. Understanding women's supplemental screening intentions following notification of dense breasts has important implications for health systems with breast screening considering the impacts of widespread notification. Personal, clinical and psychological factors should be considered when discussing both the benefits and harms of supplemental screening with women with dense breasts.