Nationwide implementation and inter-institutional gaps in care coordination for older adults with Cancer in Japan: A multi-sector survey.

INTRODUCTION: Effective coordination between hospitals and community-based providers is essential to support home-based care for older adults with cancer. We previously identified six key domains of effective coordination-system infrastructure, information exchange, communication, timeliness, human resource development, and information dissemination-highlighting anticipatory and relational elements. However, their nationwide implementation across care settings remains unclear. This study aimed to clarify the implementation status of coordination practices across these domains and to identify inter-institutional gaps among hospitals and community-based providers. MATERIALS AND METHODS: We conducted a nationwide cross-sectional survey (July-September 2025) targeting all designated cancer care hospitals (DCHs; n = 463), randomly selected home visit medical facilities (HVMFs; n = 1500), and long-term care management agencies (LTCMAs; n = 1500). Implementation of Best Practice items was assessed using a 5-point Likert scale. Rates ≥75% were classified as Higher Implementation and < 75% as Lower Implementation; differences of ≥20% were defined as inter-institutional gaps. RESULTS: A total of 1156 institutions responded (209 DCHs, 315 HVMFs, and 632 LTCMAs; response rate 33.4%). Across domains, implementation was higher for system infrastructure and information exchange related to discharge and inpatient care, whereas communication, timeliness, human resource development, and information dissemination were lower, particularly in outpatient and anticipatory phases. Discharge- or crisis-triggered processes, including standardized documentation, inpatient biomedical information exchange, and urgent communication, were classified as Higher Implementation. In contrast, outpatient-phase coordination, sharing of advance care planning (ACP) and contextual information, information and communication technology (ICT)-enabled bidirectional communication, post-transition feedback, workforce development, and patient-facing information dissemination were classified as Lower Implementation. Inter-institutional gaps ≥20% were common at the hospital-community interface, especially between DCHs and LTCMAs in ACP and contextual information sharing, and between DCHs and HVMFs in ICT-based communication and post-transition feedback. DISCUSSION: While discharge and crisis-response coordination for older adults with cancer in Japan is well-established, gaps remain in anticipatory, contextual, and bidirectional domains. These findings suggest that management for this population, which requires integration of oncologic, functional, and psychosocial care, is predominantly transition-triggered rather than trajectory-based. In aging societies such as Japan, strengthening anticipatory engagement and relational integration across medical and long-term care sectors will be critical to achieving person-centered home-based cancer care.