**Background:** Unpaid care provided by family and friends is a critical dimension of care for adults with long-term health problems and disabilities internationally. Older carers, aged 65 years and over, represent at least 20% of all carers in the UK, with estimates as high as 30%. Despite policy commitments to a whole-family approach, such as the 2014 Care Act in England, social care practice and research have historically treated carers and care-recipients as separate groups, overlooking the intertwined and interdependent nature of their lives. This scoping review aimed to identify and synthesise what is known about the quality of life (QoL) of older carers and care-recipients considered together ('dyadic QoL'), both in general and with regard to the impact of community-based social care services.
**Methods:** The review followed the five-stage methodological framework by Arksey and O'Malley (2005). The research question and terminology were developed with input from a project team and Advisory Group. The search strategy was developed through pilot searches in Scopus and adapted for 16 electronic databases, including Scopus, Web of Science, PubMed, and CINAHL Plus, supplemented by grey literature searches. Searches were conducted in October and November 2020, limited to literature published since 2000 and in English. A total of 822 items were identified and screened. Studies were included if they focused on older carers and care-recipients from a dyadic perspective and their QoL or well-being. Studies relating only to health-related QoL, clinical psychological measures, care strain/burden, or institutional settings were excluded. Fourteen papers were selected and thematically analysed in NVivo by two researchers using an agreed codebook.
**Key Results:** The 14 included papers spanned three countries (6 from the UK, 3 from the US, 1 from China) and 4 international literature reviews. Only 2 papers exclusively investigated the dyadic QoL of older carers and care-recipients. The papers included 5 quantitative studies, 5 literature reviews, 3 qualitative studies, and 1 mixed-methods study. Eight studies focused on dementia dyads. Two overarching themes were identified. First, understanding dyadic QoL was framed within 'interdependence theory', with two broad approaches: (1) dyadic data analysis, such as the Actor Partner Interdependence Model (APIM) applied by Rand et al. (2017) to 298 caring dyads, which found mutual interdependence for the 'Control over daily life' domain of QoL; and (2) the dynamics of caring relationships, drawing on social exchange theory, equity theory, and concepts of dyadic conflict and power. Second, support from family, friends, neighbours, and community-based social care services was highlighted as influencing dyadic QoL. More than a fifth of older couples in Hill's (2007) study had regular help from neighbours. Respite care and short-term breaks were consistently identified as services that positively influence dyadic QoL, though evidence on which services are most effective was mixed and limited.
**Clinical Implications:** The review emphasises that considering the QoL of carers and care-recipients together could potentially improve the understanding of care needs, provision of care services, and QoL outcomes. However, there is a significant gap between the broad consensus supporting a dyadic approach and the paucity of evidence on dyadic QoL or the impact of social care services on dyadic outcomes. The review identifies a need for future work to explore and evaluate the use of a dyadic approach in social care practice and research, including the development of frameworks for understanding and analysing dyadic QoL outcomes. The authors note that only two practice or policy-related papers were found, reflecting tensions between policy rhetoric supporting whole-family approaches and a social care system that promotes separate assessments and services for 'users' and 'carers'.