Pfizer Inc., Cambridge, MA 02139, USA.
Sensors (Basel). 2023 Oct 18;23(20):8542. doi: 10.3390/s23208542.
Wearable accelerometers allow for continuous monitoring of function and behaviors in the participant's naturalistic environment. Devices are typically worn in different body locations depending on the concept of interest and endpoint under investigation. The lumbar and wrist are commonly used locations: devices placed at the lumbar region enable the derivation of spatio-temporal characteristics of gait, while wrist-worn devices provide measurements of overall physical activity (PA). Deploying multiple devices in clinical trial settings leads to higher patient burden negatively impacting compliance and data quality and increases the operational complexity of the trial. In this work, we evaluated the joint information shared by features derived from the lumbar and wrist devices to assess whether gait characteristics can be adequately represented by PA measured with wrist-worn devices. Data collected at the Pfizer Innovation Research (PfIRe) Lab were used as a real data example, which had around 7 days of continuous at-home data from wrist- and lumbar-worn devices (GENEActiv) obtained from a group of healthy participants. The relationship between wrist- and lumbar-derived features was estimated using multiple statistical methods, including penalized regression, principal component regression, partial least square regression, and joint and individual variation explained (JIVE). By considering multilevel models, both between- and within-subject effects were taken into account. This work demonstrated that selected gait features, which are typically measured with lumbar-worn devices, can be represented by PA features measured with wrist-worn devices, which provides preliminary evidence to reduce the number of devices needed in clinical trials and to increase patients' comfort. Moreover, the statistical methods used in this work provided an analytic framework to compare repeated measures collected from multiple data modalities.
可穿戴式加速度计可实现对参与者自然环境下功能和行为的连续监测。根据研究的概念和关注点,设备通常佩戴在身体的不同部位。腰部和手腕是常用的佩戴部位:佩戴在腰部的设备可以得出步态的时空特征,而佩戴在手腕上的设备可以提供总体身体活动(PA)的测量值。在临床试验环境中部署多个设备会增加患者的负担,降低依从性和数据质量,增加试验的操作复杂性。在这项工作中,我们评估了从腰部和手腕设备中得出的特征所共享的信息,以评估是否可以通过佩戴在手腕上的设备测量的 PA 充分代表步态特征。使用 Pfizer Innovation Research (PfIRe) 实验室收集的数据作为真实数据示例,该示例从一组健康参与者获得了约 7 天来自手腕和腰部佩戴的设备(GENEActiv)的连续家庭数据。使用多种统计方法(包括惩罚回归、主成分回归、偏最小二乘回归和联合及个体变异解释(JIVE))估计手腕和腰部特征之间的关系。通过考虑多层次模型,同时考虑了组间和组内效应。这项工作表明,通常用腰部佩戴设备测量的一些选定的步态特征,可以用手腕佩戴设备测量的 PA 特征来表示,这为减少临床试验中所需设备的数量和提高患者舒适度提供了初步证据。此外,本工作中使用的统计方法提供了一个分析框架,可以比较来自多个数据模态的重复测量值。