Barriers and facilitators to shared decision-making for patients with cancer and health care providers based on the COM-B model: a systematic review.

BACKGROUND: With advancements in cancer treatment approaches, patients face increasingly complex decisions regarding their care and treatment. Although Shared Decision-Making (SDM) can help patients make more informed and optimal choices, its development remains limited, and it has not been widely integrated into clinical practice. Identifying the barriers and facilitators to SDM from the perspective of patients and health care providers (HCPs) is essential. The Capability, Opportunity, and Motivation Model of Behaviour (COM-B) provides a framework for understanding these factors. OBJECTIVE: This review aimed to explore the barriers and facilitators of SDM between patients and HCPs on the basis of the COM-B and to identify key common and dual-effect factors. METHODS: Seven databases were searched for qualitative, quantitative, and mixed-methods studies. Data on the study design and key findings were extracted and analyzed guided by the COM-B model. The findings were reported in accordance with the PRISMA guidelines. Study quality was appraised via the Mixed Methods Appraisal Tool. RESULTS: A total of 6,811 papers were identified, 32 of which met the inclusion criteria. From these studies, 64 key barriers and facilitators influencing the implementation of SDM from the perspective of patients and HCPs were extracted. These factors were systematically categorized according to the subcomponents of the COM-B model: physical capability (e.g, poor health status), psychological capability (e.g, inaccurate understanding of the disease), reflective motivation (e.g, conflicting goals), automatic motivation (e.g, fear of cancer), physical opportunity (e.g, supplemental resources), and social opportunity (e.g, good family support). CONCLUSION: Guided by the COM-B model, this study identified factors associated with SDM among patients with cancer and HCPs. Further analysis revealed that some factors are shared by both groups; interventions targeting these common factors may produce simultaneous effects on patients and HCPs, offering more implementation value. Other factors exhibit dual characteristics, acting as both facilitators and barriers depending on the context. Future efforts should focus on exploring mechanisms to address such barriers into facilitators in specific clinical settings, thereby promoting the widespread implementation of SDM. REGISTRATION NUMBER: Our protocol was registered in PROSPERO (ID: CRD42024568101).