Practice Effects on Repeated Self-Administered Digital Cognitive Assessments in Cognitively Intact Older Adults from the Framingham Heart Study: Longitudinal Observational Study.

BACKGROUND

Remote, self-administered digital assessments provide scalable approaches for monitoring cognition in older adults. Practice effects (PEs), once viewed as measurement noise, are increasingly recognized as potential markers of cognitive decline. As disease-modifying therapies for neurodegenerative conditions emerge, longitudinal digital assessments may capture subtle cognitive changes. Although the majority of PE studies have focused on memory tasks, it is critical to determine whether PEs occur in other domains. Clarifying the potential presence of PEs across multiple time points on the Food and Drug Administration-cleared Defense Automated Neurocognitive Assessment (DANA) platform remains critical for determining whether PEs can serve as a measure of cognitive decline longitudinally.

OBJECTIVE

This study aimed to examine whether PEs occur and whether demographics moderate them across quarterly self-administrations of digital cognitive tasks spanning different cognitive domains in cognitively intact older adults.

METHODS

Cognitively intact older adults from the Framingham Heart Study self-administered DANA tasks at baseline and every 3 months for 1 year (4 assessments: T1-T4). Tasks included Simple Reaction Time (SRT), Go/No-Go (GNG), and Code Substitution (CS). These tasks varied in complexity, from simple motor responding (SRT) to inhibitory control (GNG) and associative learning with working memory demands (CS). The primary outcome was Cognitive Efficiency, a derived measure of speed and accuracy, which are also recorded as secondary measures. PEs were quantified using linear mixed-effects models, and the change in mean score across time points was expressed in pooled SD units as Cohen d.

RESULTS

A total of 717 participants completed all 4 time points (mean age 64.1, SD 9.5 years; n=469, 65.4% female participants; n=481, 67.1% college-educated). PEs were observed on all tasks, with small effects on CS (d=0.43) and GNG (d=0.32) and a below-threshold effect on SRT (d=0.16). Demographics influenced baseline performance: older age predicted lower baseline scores on all tasks, females scored lower on SRT and GNG, and higher education predicted better performance on all tasks. Age was the only demographic moderator of PEs, with smaller improvements on CS among participants aged 65 years or older (B=-0.39; P<.001).

CONCLUSIONS

Quarterly self-administered digital cognitive assessments elicited measurable PEs across processing speed, inhibitory control, and visual scanning, with stronger effects on more complex tasks. Demographics influenced baseline performance, while age moderated PEs on the most demanding task. These findings provide baseline data against which PEs in clinical populations can be compared in future work, complementing prior evidence on other cognitive instruments.