The Independent and Interactive Effects of Economic Stability and Healthcare Access on 10-Year Cognitive Trajectories of Black/African American and White Older Adults from the ACTIVE Study.

Objectives: Social and structural determinants of health (SSDoH) have been linked to racial disparities in Alzheimer's disease and related dementias (ADRD). Research has established that living in an environment with greater economic stability (ES) or healthcare access (HCA) is associated with better baseline cognition, but the interactive effects between these distinct SSDoH on cognition over time have not been studied. Therefore, the present study examined the independent and interactive effects of ES and HCA on 10-year change in cognitive functioning within a large sample of racially diverse community-dwelling older adults.

Methods: Participants included 701 Black/African American and 1804 White older adults from the Advanced Cognitive Training for Independent and Vital Elderly study. Multilevel mixed effects models were used to assess associations between ES and HCA factors on individual-level memory and reasoning trajectories.

Results: Results revealed there was no significant ES × HCA interaction on longitudinal cognitive trajectories across the whole sample or within race-stratified groups, but there was a significant interaction on memory level. Higher ES levels were independently associated with slower age-related memory declines among Black/African American older adults. In contrast, higher ES and HCA levels were both independently associated with faster age-related reasoning declines among White participants.

Discussion: Results demonstrated that ES and HCA exerted synergistic effects on memory level across ages in the whole sample. Differential associations between SSDoH and cognitive outcomes across racial groups suggest that improving access to economic resources within Black/African American communities may reduce racial disparities in ADRD.