Frailty and Health Outcomes in People 65 Years or Older Living With Dementia: A Systematic Review of the Literature

Introduction: Although frailty is considered a potentially modifiable risk factor for dementia, its influence on health outcomes in individuals with established dementia remains unclear. This study aims to systematize the current evidence to understand the impact of frailty on the development of adverse outcomes in older adults with dementia. Methodology: We conducted a systematic review to investigate which adverse outcomes in 65 years or older adults with dementia are influenced by frailty. A comprehensive search was conducted across three databases—MEDLINE, EMBASE, and Cochrane—to identify relevant studies addressing this research question as of November 2024. Studies were considered for inclusion if they were observational studies or clinical trials involving individuals with dementia, assessed frailty within this population, and documented adverse health outcomes. Two independent and blinded researchers performed screening, data extraction, and risk of bias assessment. PROSPERO register CRD42024543327. Results: Our search identified 5891 articles, from which 12 were included after screening and eligibility assessment (n = 172,025 participants). Alzheimer's disease was the most studied type of dementia, and the prevalence of frailty ranged from 8% to 65.9%. The reported adverse outcomes associated with frailty in patients suffering from dementia were mortality, institutionalization, functional and cognitive decline, neuropsychiatric symptoms, reduced quality of life, caregiver burden, and hospitalization. Discussion: Understanding frailty in older adults with dementia may inform improved care strategies. Our findings suggest that higher levels of frailty are associated with an increased risk of adverse health outcomes.