A Dual Group-Based 11-Year Trajectory Analysis of Cognitive Impairment and Transport Restriction for Community-Dwelling Older Adults

Abstract

Objectives

To examine the trajectories of cognitive impairment and transport restriction over time and the interrelation between these trajectories among older adults.

Methods

Group-based trajectory modeling was used on the longitudinal National Health and Aging Trends Study (NHATS) over 11 years from 2011 to 2021, among 5753 participants, stratified by age in 2011 to three groups of 65–74 years, 75–84 years, and 85 years and above.

Results

For transport restrictions, these trajectory groups were: (1) a majority with no restrictions, (2) low and increasing or stable, and (3) moderate or high and decreasing. The overall pattern was largely consistent across the three age groups, with the older group showing a higher predicted likelihood of transport restrictions compared to the younger group. For each of the three age groups, there were two cognitive impairment trajectories including (1) low and (2) increasing cognitive impairment. The proportions of increasing cognitive impairment were 12.3% among the 65–74 years old, 27.3% among the 75–84 years old, and 40.4% among the 85 years and above old. Compared with those with no transport restriction, the other two trajectories with either low or moderate transport restrictions were more likely to belong to increasing cognitive impairment. The odds ratio was 3.06 (95% CI 2.0–4.68) for low & increasing transport restrictions versus 1.57 (95% CI 0.96–2.56) for moderate & decreasing transport restrictions among 65–74 years old. The odds ratio was 2.38 (95% CI 1.68–3.38) for low & increasing transport restrictions versus 1.88 (95% CI 1.39–2.55) for moderate & decreasing transport restrictions among 75–84 years old.

Conclusions

Cognitive impairment was more likely to co-occur with those with low and increasing transport restrictions than with those with moderate and decreasing transport restrictions. Addressing transport restriction among older adults holds the potential to ameliorate cognitive outcomes.