This is a single-center, assessor-blinded, parallel-group randomized controlled trial designed to evaluate the effectiveness of a Behavior Change Wheel-based music listening intervention for chemotherapy-related cognitive impairment in breast cancer patients. Eligible participants were adult female patients with histopathologically confirmed breast cancer who received chemotherapy. A total of 90 participants were randomly assigned in a 1:1 ratio to either the intervention group or the control group. Participants in the intervention group received routine nursing care plus a 12-week BCW-based music listening intervention, which included relationship building, health education, family involvement, individualized planning, self-training, behavioral reinforcement, and regular feedback. Participants were instructed to listen to self-selected music for at least 20 minutes per day. Participants in the control group received routine nursing care, including health education, educational materials, online support, and regular follow-up. The primary outcome was the change in Functional Assessment of Cancer Therapy-Cognitive Function total score from baseline to Week 12. Secondary outcomes included FACT-Cog subscale scores and PROMIS anxiety and depression scores. Primary analyses followed the intention-to-treat principle, and analysis of covariance was used to compare post-intervention outcomes between groups while adjusting for baseline values. The study was approved by the Ethics Committee of The First Affiliated Hospital of Nanjing Medical University. Written informed consent was obtained from all participants before enrollment. This study was registered retrospectively after completion of participant enrollment and follow-up.
