Shared Decision Making and Advance Care Planning in the Context of Promoting Home Medical Care in Japan: A Narrative Review.

Japan's rapidly aging population has heightened the need for high-quality home medical care based on patient-centered care (PCC). Shared decision making (SDM) and advance care planning (ACP) are essential processes for achieving PCC; however, their implementation in Japan remains limited. This narrative review summarizes theoretical foundations, international evidence, and current challenges in SDM and ACP, and discusses future directions for their integration into Japanese home medical care. Globally, SDM has been promoted through decision aids and policy initiatives, yet barriers such as limited consultation time, insufficient provider support, and variability in outcome measurement persist. In Japan, although professional societies have issued guidelines to promote SDM and ACP, awareness and adoption remain inadequate, partly due to entrenched informed consent practices, provider knowledge gaps, and limited patient involvement. ACP in home care has demonstrated benefits-including enhanced caregiver security, improved patient-provider communication, and greater support for home-based end-of-life care-yet real-world implementation is inconsistent. Cultural factors, such as family-centered decision making and reluctance to discuss death, further constrain uptake. Evidence increasingly emphasizes the need for integrating SDM and ACP as a continuous, iterative process, enabling both advance preparation and real-time decision making. Training programs incorporating SDM skills have shown potential to shift provider behavior toward PCC. Emerging digital and AI-based tools may expand opportunities for structured conversations and preference documentation. Advancing SDM and ACP in Japanese home medical care will require system-level reforms, workforce training, and ICT-supported care models. Japan's experience may also provide insights for other rapidly aging societies.