Kawai Hisashi, Imamura Keigo, Gong Rui, Ejiri Manami, Obuchi Shuichi
Research Team for Human Care, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 , Sakae-cho, Itabashi-ku, Tokyo, 1730015, Japan, 81 339643241 ext 4243, 81 339641844.
JMIR Form Res. 2025 Aug 18;9:e73722. doi: 10.2196/73722.
Daily-life walking speed (DWS), which is a critical health indicator in older adults, can be measured using smartphone GPS technology. Although this method is becoming more widely accessible, it is restricted to outdoor walking. In contrast, accelerometers can capture walking speed indoors; however, there is limited information on the comparability of DWS data between these two techniques.
In this study, we aimed to investigate the agreement and systematic error between DWS measured using the built-in GPS of a smartphone and an ankle-band accelerometer.
Participants were recruited from a previously selected cohort of community-dwelling older adults. Their DWS was assessed using both a smartphone app and ankle band accelerometer. Data from the two devices were matched based on simultaneous recordings, and agreement between the walking speeds was evaluated using the intraclass correlation coefficient (ICC) and a Bland-Altman plot.
A total of 99 participants (38 men, 61 women; mean [SD] age 71.5 [4.9] y) were included, yielding 3652 paired data points. The mean (SD) DWS as measured by GPS was 1.30 (0.19) m/s, and this was significantly higher than the value of 1.12 (0.23) m/s measured by the accelerometer (P<.001). The ICC(2, 1) (95% CI) value was 0.523 (-0.022 to 0.765), and the ICC(2, k) value was 0.687 (-0.045 to 0.867). The Bland-Altman plot revealed a fixed error of 0.18 m/s with 95% limits of agreement ranging from -0.49 m/s to 0.13 m/s in the GPS-measured walking speed compared to that measured by the ankle-band accelerometer.
The GPS app consistently recorded a faster walking speed than the ankle-band accelerometer. The agreement between the measurements of the two devices was poor. The data suggest that a correction is necessary when comparing the DWS between these two devices.
日常生活步行速度（DWS）是老年人健康的关键指标，可通过智能手机GPS技术进行测量。尽管这种方法越来越容易获得，但它仅限于户外步行。相比之下，加速度计可以测量室内步行速度；然而，关于这两种技术测量的DWS数据的可比性信息有限。
在本研究中，我们旨在调查使用智能手机内置GPS和脚踝加速度计测量的DWS之间的一致性和系统误差。
从先前选定的社区居住老年人队列中招募参与者。使用智能手机应用程序和脚踝加速度计评估他们的DWS。根据同步记录对来自两个设备的数据进行匹配，并使用组内相关系数（ICC）和Bland-Altman图评估步行速度之间的一致性。
共纳入99名参与者（38名男性，61名女性；平均[标准差]年龄71.5[4.9]岁），产生3652对数据点。GPS测量的平均（标准差）DWS为1.30（0.19）m/s，这显著高于加速度计测量的1.12（0.23）m/s（P<0.001）。ICC（2,1）（95%CI）值为0.523（-0.022至0.765），ICC（2,k）值为0.687（-0.045至0.867）。Bland-Altman图显示，与脚踝加速度计测量的步行速度相比，GPS测量的步行速度存在0.18 m/s的固定误差，95%一致性界限为-0.49 m/s至0.13 m/s。
GPS应用程序记录的步行速度始终比脚踝加速度计快。两种设备测量结果之间的一致性较差。数据表明，在比较这两种设备的DWS时需要进行校正。
