Racial and Ethnic Disparities in the 11-Year Bidirectional Relationship Between Dementia and Social Isolation Among Community-Dwelling Older Adults.

Abstract

Objectives: This study aims to investigate the longitudinal impact of dementia on social isolation and vice versa, with a focus on racial and ethnic variations in these relationships.

Methods: Data from 4,403 adults aged 65 and older were gathered from the National Health and Aging Trends Study (2011-2021). Dementia was categorized as no, possible, or probable, and social isolation was classified as socially isolated or not. Two cohorts were formed based on baseline social isolation and baseline dementia status. Cox proportional hazards regression models were used to evaluate the impact of baseline social isolation on subsequent dementia and vice versa, adjusting for potential covariates. Models were stratified by race/ethnicity. All analyses were conducted using STATA/MP version 17.0 RESULTS: In fully adjusted models, participants with dementia had a 1.40-fold higher likelihood of developing social isolation over the 10-year follow-up period. Those with baseline social isolation had a 7.21-fold higher likelihood of developing dementia over time. Racial and ethnic differences were observed in the influence of dementia on social isolation incidence. Non-Hispanic whites showed a statistically significant increase, while other racial and ethnic groups did not exhibit significant changes. Conversely, the impact of social isolation on dementia incidence was significant across all racial and ethnic groups.

Discussion: Dementia and social isolation are bidirectionally linked among older adults, with notable racial and ethnic differences. Dementia increases the risk of social isolation, particularly among non-Hispanic whites, while social isolation significantly elevates the risk of developing dementia across all racial and ethnic groups. These findings underscore the need for targeted interventions to address social isolation and cognitive decline, considering racial and ethnic differences to improve outcomes for seniors.