Technological advances in multimodal wearable and connected devices have enabled the measurement of human movement and physiology in naturalistic settings. The ability to collect continuous activity monitoring data with digital devices in real-world environments has opened unprecedented opportunity to establish clinical digital phenotypes across diseases. Many traditional assessments of physical function utilized in clinical trials are limited because they are episodic, therefore, cannot capture the day-to-day temporal fluctuations and longitudinal changes in activity that individuals experience. In order to understand the sensitivity of gait speed as a potential endpoint for clinical trials, we investigated the use of digital devices during traditional clinical assessments and in real-world environments in a group of healthy younger (n = 33, 18–40 years) and older (n = 32, 65–85 years) adults. We observed good agreement between gait speed estimated using a lumbar-mounted accelerometer and gold standard system during the performance of traditional gait assessment task in-lab, and saw discrepancies between in-lab and at-home gait speed. We found that gait speed estimated in-lab, with or without digital devices, failed to differentiate between the age groups, whereas gait speed derived during at-home monitoring was able to distinguish the age groups. Furthermore, we found that only three days of at-home monitoring was sufficient to reliably estimate gait speed in our population, and still capture age-related group differences. Our results suggest that gait speed derived from activities during daily life using data from wearable devices may have the potential to transform clinical trials by non-invasively and unobtrusively providing a more objective and naturalistic measure of functional ability.

多模式可穿戴和连接设备的技术进步使得在自然环境中测量人体运动和生理成为可能。在现实环境中使用数字设备收集连续活动监测数据的能力为建立跨疾病的临床数字表型提供了前所未有的机会。临床试验中使用的许多传统的身体功能评估都是有限的，因为它们是间歇性的，因此无法捕捉个体经历的日常时间波动和活动的纵向变化。为了了解步态速度作为临床试验潜在终点的敏感性，我们调查了一组健康年轻人（ n = 33、18-40 岁）在传统临床评估期间和现实环境中数字设备的使用情况和年龄较大（ n = 32、65-85 岁）的成年人。在实验室执行传统步态评估任务期间，我们观察到使用腰部安装的加速度计估计的步态速度与金标准系统之间具有良好的一致性，并且发现实验室和家庭步态速度之间存在差异。我们发现，在实验室中估计的步态速度，无论有没有数字设备，都无法区分年龄组，而在家监测过程中得出的步态速度能够区分年龄组。此外，我们发现仅三天的家庭监测就足以可靠地估计我们人群的步态速度，并且仍然捕获与年龄相关的群体差异。 我们的结果表明，使用可穿戴设备的数据从日常生活活动中得出的步态速度可能有潜力通过非侵入性和不引人注目地提供更客观和自然的功能能力测量来改变临床试验。