Currently submitted to: JMIR Research Protocols
Date Submitted: Aug 25, 2026
Open Peer Review Period: Aug 25, 2026 - Oct 20, 2026
(currently open for review)
Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Protocol for the Technologies for Aging Health – Digital Approaches (TAH-DA) Study
ABSTRACT
Background:
Age-related cognitive decline develops over decades and precedes mild cognitive impairment and dementia. Consumer wearable devices provide an opportunity to continuously measure physiological and behavioral signals that may be associated with cognitive function, while remotely delivered digital interventions may offer scalable approaches to support cognitive health.
Objective:
The Technologies for Aging Health – Digital Approaches (TAH-DA) study aims to 1) determine whether physiological and behavioral measures obtained from consumer smartwatch technology can predict cognitive function across midlife and older adulthood and 2) quantify the effects of digital cognitive interventions on cognitive trajectories and corresponding smartwatch-derived biometrics.
Methods:
TAH-DA is a 50-week, fully remote randomized controlled trial designed to enroll 1,000 adults aged 40–89 years, with 200 participants per decade of life. Participants will wear a Samsung Galaxy smartwatch daily and nightly from weeks 5–50 to collect multimodal physiological and behavioral data, including heart rate and heart rate variability, actigraphy-derived activity and sleep measures, skin temperature, peripheral oxygen saturation, and bioelectrical impedance. Participants will also complete repeated tablet-based cognitive assessments and surveys. After a 10-week baseline phase, participants will be randomized to receive either experimental or active control digital interventions during a 12-week intervention phase, which will be followed by an 8-week post-intervention assessment period. Next, participants will engage in a 12-week booster intervention phase followed by an 8-week follow-up assessment period. Baseline analyses will evaluate the ability of individual and multimodal smartwatch-derived measures to predict cognitive performance using regression, mixed-effects, and machine-learning approaches. Longitudinal analyses will assess intervention-related changes in cognitive performance and smartwatch-derived biometrics across baseline, post-intervention, and follow-up.
Results:
Data collection began in April 2026 and is expected to continue through April 2028. As of July 2026, 175 participants had enrolled, and study results are in progress.
Conclusions:
The TAH-DA study will evaluate whether consumer wearable technology can provide scalable, ecologically valid digital markers of cognitive function and whether remotely delivered adaptive cognitive interventions can alter cognitive trajectories and corresponding physiological measures across adulthood. By integrating continuous real-world sensing with repeated cognitive assessment and digital intervention in a large adult lifespan sample, this study may inform future approaches to remote monitoring of cognitive change and accessible strategies for supporting cognitive health during aging. Clinical Trial: Open Science Framework https://osf.io/4wxnr
Citation
Request queued. Please wait while the file is being generated. It may take some time.
Copyright
© The authors. All rights reserved. This is a privileged document currently under peer-review/community review (or an accepted/rejected manuscript). Authors have provided JMIR Publications with an exclusive license to publish this preprint on it's website for review and ahead-of-print citation purposes only. While the final peer-reviewed paper may be licensed under a cc-by license on publication, at this stage authors and publisher expressively prohibit redistribution of this draft paper other than for review purposes.