ABSTRACTBackground:Dementia is a major health problem with a growing number of people affected by the condition, both directly and indirectly through caring for someone with dementia. Many live at home but little is known about the range and intensity of the support they receive. Previous studies have mainly reported on discrete services within a single geographical area. This paper presents a protocol for study of different services across several sites in England. The aim is to explore the presence, effects, and cost-effectiveness of approaches to home support for people in later stage dementia and their carers.Methods:This is a prospective observational study employing mixed methods. At least 300 participants (people with dementia and their carers) from geographical areas with demonstrably different ranges of services available for people with dementia will be selected. Within each area, participants will be recruited from a range of services. Participants will be interviewed on two occasions and data will be collected on their characteristics and circumstances, quality of life, carer health and burden, and informal and formal support for the person with dementia. The structured interviews will also collect qualitative data to explore the perceptions of older people and carers.Conclusions:This national study will explore the components of appropriate and effective home support for people with late stage dementia and their carers. It aims to inform commissioners and service providers across health and social care.