Subjective Cognitive Impairment (SCI) and Future Dementia Risk in the National Health and Aging Trends Study (NHATS) During 2012-2019.

Abstract

BackgroundSubjective cognitive impairment (SCI), assessed in national surveys, offers potential for dementia monitoring and early detection. However, its causal link to dementia risk remains unclear.ObjectiveTo evaluate whether SCI causally affects dementia risk in U.S. older adults (≥65 years), considering mortality as a competing risk.MethodsUsing data from 1622 dementia-free older adults in the National Health and Aging Trends Study (NHATS) during 2011-2019, we estimated total, direct, and separable effects of SCI on dementia and mortality risks.ResultsSCI was reported by 7.6% at baseline and associated with a twofold increased dementia risk over 8 years (RR: 1.95, 95% CI: 1.07-3.07) and lower mortality risk (RR: 0.31, 95% CI: 0.10-0.67). Direct effect analysis indicated a potential direct causal link between SCI and dementia.ConclusionsSCI predicts dementia onset and inversely affects mortality, highlighting the importance of early detection and precise analytic approaches.