Facilitators of and Barriers to Advance Care Planning Engagement in Patients with Advanced Non-Cancer Illnesses: A Systematic Review with Thematic Synthesis

Background/Objectives: Advance care planning (ACP) is an important component of person-centered care; however, engagement remains challenging among patients with advanced non-cancer illnesses, their family caregivers, and healthcare professionals. This systematic review aimed to synthesize evidence on facilitators of and barriers to ACP engagement across these stakeholder groups. Methods: This systematic review with thematic synthesis was registered in PROSPERO (CRD420261346283) and reported in accordance with PRISMA 2020. PubMed, Scopus, and ScienceDirect were searched for qualitative, quantitative observational, and mixed-methods studies published between 1 January 2015 and 2 November 2026. The final database searches were conducted on 2 November 2026. Methodological quality was assessed using Joanna Briggs Institute critical appraisal tools, and findings were integrated through thematic synthesis. Results: Twelve studies were included, comprising ten qualitative studies, one cross-sectional study, and one mixed-methods study. Six interconnected analytical themes were identified: (1) readiness development, (2) negotiated social processes, (3) professional legitimacy and capability, (4) system-dependent practice, (5) cultural meaning, and (6) social legitimacy. Key facilitators included understanding of illness and ACP, supportive family involvement, trust-based communication, professional confidence, interdisciplinary collaboration, and organizational support. Barriers included limited awareness, emotional discomfort, family gatekeeping, prognostic uncertainty, unclear professional responsibilities, resource constraints, fragmented care, and culturally shaped concerns about death and future care. Broader social and policy contexts further influenced the perceived acceptability and implementation of ACP. Conclusions: ACP engagement among patients with advanced non-cancer illnesses is a dynamic, relational, and context-dependent process shaped by interacting individual, interpersonal, professional, organizational, cultural, and societal influences. Strengthening engagement may require iterative discussions tailored to evolving readiness, family involvement aligned with patients’ preferences, improved professional capability and role clarity, coordinated healthcare processes, and culturally responsive approaches supported by organizational and policy frameworks.