AbstractObjectiveTo provide an overview of the current state of research of advance care planning (ACP), highlighting most studied topics, publication time, quality of studies and reported outcomes, and to identify gaps to improve ACP receptivity, utilization, implementation, and outcomes.MethodCochrane methodology for conducting overviews of systematic reviews. Study quality was assessed using a modified version of the Assessing the Methodological Quality of Systematic Reviews tool. The following databases were searched from inception to April 2017: MEDLINE, EBM Reviews, Cochrane Reviews, CINAHL, Global Health, PsycINFO, and EMBASE. Searches were supplemented with gray literature and manual searches.ResultEighty systematic reviews, covering 1,662 single articles, show that ACP-related research focuses on nine main topics: (1) ACP as part of end-of-life or palliative care interventions, (2) care decision-making; (3) communication strategies; (4) factors influencing ACP implementation; (5) ACP for specific patient groups, (6) ACP effectiveness; (7) ACP experiences; (8) ACP cost; and (9) ACP outcome measures. The majority of this research was published since 2014, its quality ranges from moderate to low, and reports on documentation, concordance, preferences, and resource utilization outcomes.Significance of resultsDespite the surge of ACP research, there are major knowledge gaps about ACP initiation, timeliness, optimal content, and impact because of the low quality and fragmentation of the available evidence. Research has mostly focused on discrete aspects within ACP instead of using a holistic evaluative approach that takes into account its intricate working mechanisms, the effects of systems and contexts, and the impacts on multilevel stakeholders. Higher quality studies and innovative interventions are needed to develop effective ACP programs and address research gaps.