Association of informal caregiver distress with health outcomes of community‐dwelling dementia care recipients: a systematic review

Background: Most dementia care occurs in the community with support from informal caregivers who are often distressed. Dementia caregiver distress is known to be hazardous to the caregiver's health, but the impact on the dementia care recipient is not well known. Methods: the Medline, Embase, PsycINFO, CINAHL, and Cochrane databases were searched from inception until June 2017 for studies investigating the association of informal caregiver distress with health outcomes of community‐dwelling dementia care recipients. The search results were screened and then data abstracted, and the risk of bias was appraised independently by pairs of reviewers. Results: 81 original investigations were included (n = 43 761 caregivers and dementia care recipients). Sixty‐six studies (81.5%) were observational or cross‐sectional in design, and 47 studies (58%) had a low risk of bias. There was considerable clinical and methodological heterogeneity precluding quantitative synthesis. Dementia care recipients (n = 21 881) had a mean age of 78.2 years (SD ± 3.8 y), half (50.0%) were women, and two‐thirds (66.1%) had Alzheimer's disease. The dementia caregivers (n = 21 880) had a mean age of 62.5 years (SD ± 23.3), three‐quarters (74.1%) were women, and one‐half (50.5%) were spouses of the dementia care recipient. Twenty‐two unique dementia care recipient outcomes were studied including cognition, mood, quality of life, function, healthcare utilisation, and costs. Overall, informal caregiver distress is commonly associated with the institutionalization of the dementia care recipient, worsening behavioural and psychological symptoms of dementia, and experiencing elder abuse. Conclusion: Informal caregiving is a cornerstone of dementia care, and distress related to this role is associated with worsening of several dementia care recipient health outcomes. It is important that clinicians and researchers worldwide consider the broader consequences of caregiver distress.