Individual-level Social Vulnerability and Cognitive Function Among Older Adults in the United States National Health and Nutrition Examination Survey

Background: Cognitive function is crucial for healthy aging, and its impairment reduces quality of life and increases healthcare and societal burden. Social vulnerability, shaped by factors like income, education, and access to healthcare, has been associated with cognitive health, but reliance on community-level assessments may limit understanding of risk at the individual level. Objectives, Design, Setting, Participants: We examined the cross-sectional association between a proposed individual-level Social Vulnerability Index (iSVI) and cognitive function among 5,989 participants aged [≥]60 years in the US National Health and Nutrition Examination Survey (NHANES) 1999-2002 and 2011-2014 cycles. Measurements: Cognitive performance was measured using the Digit Symbol Substitution Test (DSST). iSVI was constructed by summing six risk indicators (income, education, health insurance, employment, housing tenure, and food security). Health insurance and employment were scored on a three-level scale (0/0.5/1); other indicators were binary (0/1). Survey-weighted linear regression estimated associations between iSVI and DSST scores, adjusting for age, sex, race and Hispanic origin, and survey cycle. Estimates were benchmarked against adjusted associations between age and DSST. Results: Higher iSVI was associated with poorer cognition, with each one-unit increase corresponding to a 5.30-point lower DSST score (95% CI: -5.71, -4.89). This difference was comparable to nearly 5 years of age-related difference in DSST performance, as each additional year of age was associated with a 1.08-point lower DSST score (95% CI: -1.14, -1.03). Conclusions: Increased iSVI was associated with lower cognitive function in older adults, highlighting individual-level social vulnerability as a key intervention opportunity to prevent cognitive impairment.