NG00062 - Episodic Memory Trajectories (EMTs) of 13,037 elderly


The primary goal of the study was to identify trajectories for episodic memory performance in a large and ethnically diverse sample of older adults. The secondary goals were: 1) to investigate whether socio-demographic factors and APOE genotype are predictors of age-related memory decline and 2) to investigate incident rates of dementia.

Longitudinal data on episodic memory performance was gathered from five different study cohorts: The Washington Heights-Inwood Columbia Aging Project (WHICAP), The Chicago Health and Aging Project (CHAP), The National Institute on Aging Late-Onset Alzheimer Disease Family Based Study (NIA-LOAD), The National Alzheimer's Coordinating Center (NACC) and The Rush Alzheimer’s Disease Center cohorts (ROSMAP).

Trajectories of episodic memory performance over time were estimated in a large sample of 13,037 ethnically diverse elderly (average ages 72 to 85 years) using Latent Class Mixed Models. Analysis was conducted using two samples at baseline evaluation: i) non-cognitively impaired individuals, and ii) all individuals regardless of dementia status. Two major episodic memory trajectories were estimated: 1) Stable - consisting of individuals exhibiting a constant or improved memory function, and 2) Decliner - consisting of individuals whose memory function declined. The majority of the study participants maintain their memory performance over time. Compared to those with Stable trajectory, individuals characterized as Decliners were more likely to have non-white ethnic background, fewer years of education, a higher frequency of ε4 allele at APOE gene and five times more likely to develop dementia.

Submission date: 
Study cohort Number of Samples
NACC 5355
CHAP 3268
LOAD 691