Assessing quality of life-a scoping review of studies presenting quality of life instruments for informal caregivers of persons with dementia.

BACKGROUND: Assessing the quality of life in informal caregivers of people with dementia is crucial, as it may signal the need for support, counselling, and other care-related needs for their loved ones. Although various quality-of-life instruments are available, selecting an appropriate instrument suited to this population is a complex and challenging task. Therefore, this scoping review aims to identify and map the existing literature on instruments used to measure the quality of life of informal caregivers of people living with dementia. METHOD: Seven databases (Medline, Embase, PsycINFO, CINAHL, SocIndex, Web of Science, Epistemonikos) were searched for original, relevant, peer-reviewed articles in English published between May 2016 and January 2025. This scoping review adhered to international methodological guidelines and is presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. RESULTS: A total of 34 studies, reporting on 21 instruments used to assess quality of life in informal caregivers of people with dementia, are included. These comprise four generic instruments (CASP-16, SF-12, SF-36, and WHOQOL-BREF) and 17 disease- and population-specific instruments. The SF-36, the WHOQOL-BREF, and the C-DEMQOL were the most frequently used, appearing in five studies each. Overall, there was limited evidence regarding the instruments' internal consistency and content validity, and the review results suggested that none stood out as superior for use with informal caregivers of people with dementia. CONCLUSION: Several instruments have been used to assess the quality of life in informal caregivers of people with dementia; however, few were specifically developed or validated for this population. No instrument emerged as clearly superior, and evidence on content validity and internal consistency was generally limited. Instruments tailored to caregivers, such as the APPLIQUE, ASCOT-Carer, LTCQ-Carer, and SCQOLS-D, showed greater relevance to caregiving experiences. At the same time, generic instruments like the WHOQOL-BREF often included less applicable items and lacked validation in this context. These findings emphasise the need for careful instrument selection, with a focus on relevance to caregiving domains, and highlight the importance of future research that includes qualitative input, caregiver involvement, and robust psychometric testing across diverse settings. PROSPERO REGISTRATION: CRD42022327590.