Assessing the impact of caregiving on informal caregivers of adults with a mental disorder in OECD countries: A systematic literature review of concepts and their respective questionnaires.

We conducted a systematic literature review to identify and review the concepts and questionnaires used to assess the impact of caregiving on caregivers for adults with a mental disorder. With our study, we aimed to provide an overview and categorize the conceptualization and operationalization of the impact of caregiving, with special attention for the complexity and multi-conceptualization of concepts. Embase, Medline, PsycInfo, Web of Science Core Collection, Cochrane Central Register of Trials, Cinahl Plus, Econlit and Google Scholar were systematically searched for articles from 1 January 2004 to 31 December 2019. Eligible articles were peer-reviewed studies that assessed the impact of caregiving for informal caregivers of adults with a reported mental disorder by means of a questionnaire. The complete study protocol can be found on PROSPERO (CRD42020157300). A total of 144 questionnaires were identified that assessed the impact of caregiving. Based on similarities in meaning, concepts were classified into 15 concept clusters. The most frequently assessed concept clusters were mental health, caregiving burden, other caregiving consequences, family impact, and overall health-related outcomes. The use of concept clusters differed per diagnosis group, with diagnoses, such as schizophrenia, using a wide range of caregiving impact concepts and other diagnoses, such as personality disorders, only using a limited range of concepts. This is the first study that identified and reviewed the concepts and questionnaires that are used to assess the impact of caregiving. Caregiving is researched from a broad array of perspectives, with the identification of a variety of concepts and dimensions and use of non-specific questionnaires. Despite increasing interest in this field of research, a high degree of variability remains abundant with limited consensus. This can partially be accredited to differences in the naming of concepts. Ultimately, this review can serve as a reference to researchers who wish to assess the impact of caregiving and require further insight into concepts and their respective questionnaires.