Effectiveness of evidence-based decision aids for women with pathogenic BRCA1 or BRCA2 variants in the german health care context: results from a randomized controlled trial

Background Women with pathogenic BRCA1 or BRCA2 variants are at high risk for breast and ovarian cancer. Preventive options include risk-reducing breast and ovarian surgeries and intensified breast surveillance. However, individual decision-making is often associated with decisional conflicts. Two evidence-based decision aids have recently been developed for these women (healthy or with unilateral breast cancer) for the German context to support them in their decision-making process. This study evaluated their effectiveness. Methods In a randomized controlled study, women (aged 18-70 years) with pathogenic BRCA1 or BRCA2 variants were randomly assigned 1:1 to the intervention (IG, n = 230) or control (CG, n = 220) group. All participants received usual care. After baseline survey (t0), IG participants additionally received the DAs. Follow-up surveys were at three (t1) and six (t2) months. Primary outcome was decisional conflict at t1. Secondary analyses included decision status, decision regret, knowledge on risks and preventive options, self-reported psychological symptoms, acceptability of DAs, and preparation for decision-making. Results Of 450 women recruited, 417 completed t0, 398 completed t1 and 386 completed t2. Compared to CG, IG participants had lower decisional conflict scores at t1 (p = 0.049) and t2 (p = 0.006) and higher scores for knowledge (p = 0.004), acceptability (p = 0.000), and preparation for decision-making (p < 0.01). Conclusions These DAs can help improve key parameters of decision-making in women with pathogenic BRCA1 and BRCA2 variants and, thus, provide a useful add-on to the current counseling and care concept for these women in Germany. Trial registration German Clinical Trials Register, DRKS-ID: DRKS00015823, retrospectively registered 14/06/2019. Keywords: BRCA1 and BRCA2 variants, Decision aids, Decisional conflict, Decision-making, Hereditary breast and ovarian cancer, Preventive options, Preference-sensitive decisions