Assessment of Wearable Device Adherence for Monitoring Physical Activity in Older Adults: A Pilot Cohort Study (Preprint)

BACKGROUND Physical activity has emerged as a modifiable behavioral factor to improve cognitive function. However, research into the adherence to remote monitoring of physical activity in older adults remains limited. OBJECTIVE This study aimed to assess the adherence in remote monitoring of physical activity in older adults within a pilot cohort from objective user data, providing insights for the scalability of such monitoring approaches in larger, more comprehensive future studies. METHODS This study included 22 participants from the Boston University Alzheimer’s Disease Research Center (BU ADRC) Clinical Core. These participants opted into wearing the Verisense watch as part of their everyday routine during 14-day intervals every three months. Eighteen continuous physical activity measures were assessed. Adherence was quantified daily and cumulatively across the follow-up period. The coefficient of variation was used as a key metric for assessing data consistency across participants over multiple days. Day-to-day variability was estimated by calculating intraclass correlation coefficients using a two-way random-effects model for the baseline, second, and third days. RESULTS Adherence to the study on a daily basis outperformed cumulative adherence levels. The median proportion of adherence days (wearing time surpassed 90% of the day) stood at 92.1%, with an interquartile range spanning from 86.9% to 98.4%. However, at the cumulative level, 31.8% of participants in this study exhibited lower adherence, with the device worn on fewer than 4 days within the requested initial 14-day period. Five physical activity measures have high variability for some participants. Consistent activity data for four physical activity measures might be attainable with just a three-day period of device use. CONCLUSIONS This study revealed that while older adults generally showed high daily adherence to the wearable device, consistent usage across consecutive days proved difficult. These findings underline the effectiveness of wearables in monitoring physical activity in older populations and emphasize the ongoing necessity to simplify usage protocols and enhance user engagement to guarantee the collection of precise and comprehensive data.