Background: Shared decision-making is an essential part of patient care. Patients need more information to support their decision-making about treatment options. An Arabic language decision aid (DA) for metastatic colorectal cancer patients (mCRC) was developed, considering systemic therapy (chemotherapy with or without targeted therapy) as a choice of treatment to assess its role in patients' decision-making. Methods: A multicenter randomized controlled trial was conducted in four out patients in oncology clinics in Saudi Arabia to measure patient certainty when selecting their treatment options and the satisfaction and willingness of oncology physicians using the Arabic DA among mCRC patients. Results: Ninety-two patients with mCRC considering first-line systemic therapy were randomly allocated to the intervention arm (DA with usual care) or control arm (usual care alone). The outcome measured the patients' certainty regarding their decision: Decisional Conflict Scale (DCS). 51 (55%) were randomized to the DA arm. Both arms scored low in the DCS, with less than 40 (score range 1-100). However, the DA arm scored lower (range 15.1-24.3), on the overall DCS and the DCS sub-scores than the usual care arm (18.8 and 37.6). The values clarity subscale was significantly lower in the DA arm (p = 0.030). Conclusion: This trial found significant difference with the DA's use in mCRC patients' rate of decisional conflict in the domain of clarity lower than patients receiving usual care, which could enhance a patients' ability to make treatment-related decisions. Our recommendation is to include the DA with usual care for mCRC patients as a part of the initial consultation to support shared decision making.

Keywords: Colorectal neoplasms, Decision support techniques, Decisional Conflict, Shared decision making, patient care management, Decision Aid