Multinational cohort study of health perception mismatch trajectories and risks of cognitive decline, depression, and mortality

BACKGROUND: Health perception mismatch is common in older adults, yet its longitudinal patterns and prognostic value remain unclear. This study aimed to identify distinct mismatch trajectories and their associations with depression, cognitive decline, and mortality. METHODS: Data from three longitudinal ageing cohorts-the China Health and Retirement Longitudinal Study (CHARLS), English Longitudinal Study of Ageing (ELSA), and Health and Retirement Study (HRS)-were used to identify health perception mismatch trajectories and evaluate their associations with depression, cognitive impairment, and mortality. Baseline SRH-ADL/IADL interplay was examined within these longitudinal cohorts, while the National Health and Nutrition Examination Survey (NHANES) was retained as an independent external cross-sectional comparison. Associations were evaluated using multivariable regression, structural equation modeling, inverse probability of treatment weighting, causal forests, random-effects meta-analysis, and counterfactual prediction. FINDINGS: Baseline analyses in CHARLS, ELSA, and HRS showed heterogeneous and generally modest SRH-ADL/IADL additive interaction estimates, while NHANES provided an independent external cross-sectional comparison. Three stable perception mismatch trajectories, Mildly pessimistic, Mildly optimistic, and Highly optimistic, were consistently identified across CHARLS, ELSA, and HRS. Despite reporting better SRH, individuals in the Highly optimistic group had poorer baseline health and higher subsequent risks of depression, cognitive decline, and mortality. Counterfactual prediction analyses indicated 13-18% differences in mortality and depression risk between hypothetical trajectory contrasts, with the largest differences observed between the mildly pessimistic and highly optimistic classes, suggesting that discordantly favorable SRH may mark elevated risk. INTERPRETATION: Health perception mismatch trajectories may help identify older adults at elevated health risk. Discordantly optimistic perceptions may mark underlying vulnerability, suggesting that combining subjective and objective assessments could complement existing approaches to risk stratification. However, these observational findings do not establish that modifying health perceptions or trajectory membership would alter subsequent outcomes.