Cognitive Decline and ADL Independence in Older Adults: A Systematic Review

Abstract

Background: Cognitive decline is prevalent among older adults and is associated with decreased independence in activities of daily living (ADL).

Objective: To systematically review the association between cognitive decline and ADL independence in older adults.

Methods: This systematic review followed PRISMA 2020 guidelines. Literature searches were conducted in PubMed, ScienceDirect, and Google Scholar for studies published between 2021 and 2026. Eligible studies included older adults aged ≥60 years assessing cognitive function and ADL independence. A qualitative synthesis was performed due to heterogeneity. Risk of bias was assessed using an adapted Newcastle–Ottawa Scale for cross-sectional studies.

Results: Five cross-sectional studies with sample sizes ranging from approximately 60 to over 10,000 participants were included. Cognitive function was assessed using standardized tools such as the Mini-Mental State Examination (MMSE), while ADL was measured using instruments such as the Barthel Index. All studies reported a consistent association between cognitive impairment and reduced ADL independence. However, quantitative effect measures (e.g., odds ratios, confidence intervals) were not consistently reported. Risk of bias assessment indicated moderate to high risk across most studies.

Conclusion: Cognitive decline is associated with reduced ADL independence in older adults. However, the strength of evidence is limited due to study design, lack of quantitative synthesis, and risk of bias in included studies.