Screening participant and health service impact of population-based breast density notification in Australia: a randomised controlled trial in BreastScreen Queensland

Intervention 1 (study arm 2) - n=952: Women attending a BreastScreen Queensland Sunshine Coast service will have their breast density assessed. Those who are classified into BI-RADS category C or D (heterogeneously dense and extremely dense) will be randomised. Intervention 1 will include a notification of breast density plus a hard-copy written insert including health literacy sensitive breast density information. Participants will receive their breast density notification within the standard mammogram outcome letter sent by BreastScreen Queensland approximately 4-6 weeks following their mammogram. An additional insert will be included in this letter that is health literacy sensitive (lay language with a grade 8 reading level or below) and provides additional information about breast density. Staff at BreastScreen Queensland will send the letter and additional insert to participants at their home address or email address (as preferred). Participants will then be contacted by the researchers at 8-weeks, 12-months and 27-months to collect self-reported data via an online questionnaire. At 8-weeks participants in Intervention 1 (study arm 1) will also indicate whether their willingness to participate in the longitudinal qualitative sub-study component of the trial where n=30 women will be involved in a series of short semi-structured telephone interviews at 8-10 weeks, 12-months and 27-months. Women will be purposively selected from those willing to participate to ensure a range of sociodemographic characteristics and responses. Intervention 2 (study arm 3) - n=952: Women attending a BreastScreen Queensland Sunshine Coast service will have their breast density assessed. Those who are classified into BI-RADS category C or D (heterogeneously dense and extremely dense) will be randomised. Intervention 2 will include a notification of breast density plus online written and video-based health literacy sensitive breast density information. Participants will receive their breast density notification within the standard mammogram outcome letter sent by BreastScreen Queensland approximately 4-6 weeks following their mammogram. This letter will also include instructions (a link and QR code) to a short (~2 minute) online video with the identical information in a more conversational format. Staff at BreastScreen Queensland will send the letter with instructions to go online to participants at their home address or email address (as preferred). Women will then be contacted by the researchers at 8-weeks, 12-months and 27-months to collect self-reported data via an online questionnaire. At 8-weeks participants in Intervention 2 (study arm 3) will also indicate whether their willingness to participate in the longitudinal qualitative sub-study component of the trial where n=30 women will be involved in a series of short semi-structured telephone interviews at 8-10 weeks, 12-months and 27-months. Women will be purposively selected from those willing to participate to ensure a range of sociodemographic characteristics and responses.