Introduction

For decades now, the provision of effective and accessible home care services for older adults has been touted as a solution to the challenges posed by aging populations. However, in light of the recent hecatomb of COVID-19 deaths in long-term care institutions, the importance and urgency of optimizing home care services is stronger than ever.
In this context, we conducted a large scale and broadly focused, realist-inspired narrative review aimed at answering three questions. First, what is home care? Though the term is commonly used as if the definition was self-evident, the nature, boundaries and objectives of home care vary a lot depending on jurisdictions and authors. Second, what evidence exists on the effectiveness of home care models and interventions? Many intervention-specific systematic reviews have been published but few policy-level efforts exist that integrate insights into the links between home care models and their outcomes. Third, what is known about the causal processes involved in the production of those effects? This last question aims at summarizing available evidence to inform intervention design, optimization and evaluation. In conclusion, our analysis suggests that three mechanisms (system integration, case management and relational continuity) are core characteristics of home care models’ effectiveness.