Raw Data Used for Statistical Analyses.

ObjectiveThis study aims to identify the factors associated with decision regret among colorectal cancer patients undergoing chemotherapy in China and to determine whether decision self-efficacy mediates the relationship between social support and decision regret.MethodsA cross-sectional study was conducted using convenience sampling with 243 colorectal cancer patients receiving chemotherapy. From 29 July 2025–2 October 2025., all participants were recruited from a tertiary hospital in Inner Mongolia, China. Data were collected through a sociodemographic and clinical questionnaire, the Social Support Scale, the Decision Self-Efficacy Scale, and the Three-Dimensional Decision Regret Scale. Non-parametric tests were employed to analyze associated factors, and mediation analysis was performed using SPSS and AMOS.ResultsEducational attainment, occupational status, and monthly income were significantly associated with decision regret among patients. Further analysis revealed a negative association between social support and decision regret in individuals undergoing chemotherapy for colorectal cancer (β = –0.306, p ConclusionNotable interactions were observed among social support, decision self-efficacy, and decision regret, with decision self-efficacy serving as the mediating mechanism. Clinicians are encouraged to prioritize strengthening both external social support and patients’ internal decision self-efficacy, which were associated with lower decision regret and better quality of life. Additionally, particular attention should be directed toward individuals with lower income, limited employment, or lower educational attainment, as they demonstrate a heightened vulnerability to experiencing decision regret.