Perceived Barriers for Advance Care Planning Among People with Dementia and Family Caregivers: A Systematic Review of Qualitative Studies

Background: Advance care planning (ACP) enables individuals to communicate values and preferences for future care before decisional capacity is lost. Although ACP is particularly important for people living with mild cognitive impairment (MCI) and dementia, engagement remains low, and the mechanisms underlying this gap are not well understood. This qualitative evidence synthesis examined perceived barriers to ACP among people living with dementia and their family caregivers.Methods: Four were searched from database inception to July 1st 2026, for qualitative studies reporting barriers to ACP among people with MCI or dementia and/or family caregivers. Twenty-four studies conducted across ten countries met inclusion criteria. Barrier statements extracted from included studies were analyzed using thematic synthesis, generating 25 codes grouped into descriptive themes and further abstracted into analytical themes representing dementia-specific mechanisms.Results: Two analytical themes were identified: (1) challenges in preserving the person's voice throughout the dementia trajectory, reflecting a shift toward caregiver-mediated decision-making, assumptions about capacity, and delayed ACP initiation; and (2) challenges in maintaining continuity of expressed values and preferences over time, reflecting uncertainty about future care needs and the limitations of one-time ACP conversations. Three contextual barriers, including limited ACP preparedness, insufficient healthcare professional and system support, and sociocultural influences, further shaped engagement. Methodological quality across included studies was high.Conclusion: ACP in dementia is shaped by challenges extending beyond commonly reported general-population barriers. Effective support for this population requires moving beyond one-time, capacity-focused documentation toward ongoing, relationally embedded approaches to communication and values clarification throughout the disease trajectory.