Mobility limitation trajectories and longitudinal changes in delayed recall in midlife and later life: A multicohort study.

OBJECTIVES: Mobility limitation has been linked to cognitive decline, but evidence largely relies on single-time-point assessments. Whether longitudinal mobility patterns are associated with memory change remains unclear.

STUDY DESIGN: This multicohort longitudinal study included 25,990 adults aged 45 years or more from the China Health and Retirement Longitudinal Study, the U.S. Health and Retirement Study, and the English Longitudinal Study of Ageing. Mobility limitation trajectories were identified in the China Health and Retirement Longitudinal Study using group-based trajectory modeling and applied to the other two cohorts to assess cross-cohort transportability.

MAIN OUTCOME MEASURES: Delayed recall was measured using a common 10-word recall task scored on a 0-10 scale. Linear mixed-effects models examined concurrent associations between trajectory membership and change in delayed recall, adjusted for sociodemographic, lifestyle, and health-related factors.

RESULTS: Three trajectories were identified: stable-low limitation, progressive deterioration, and persistent-high limitation. In fully adjusted complete-case models, the persistent-high limitation group showed a faster decline in delayed recall than the stable-low limitation group in the China Health and Retirement Longitudinal Study (β = -0.115; 95% confidence interval -0.152 to -0.079), the Health and Retirement Study (β = -0.026; 95% confidence interval -0.034 to -0.017), and the English Longitudinal Study of Ageing (β = -0.045; 95% confidence interval -0.058 to -0.031). Subgroup analyses suggested effect modification by age, education, and heart disease.

CONCLUSIONS: Longitudinal mobility limitation patterns were associated with change in delayed recall across three aging cohorts. Repeated mobility assessment may help characterize the co-evolution of physical and cognitive functioning in midlife and later life.