Breteler Martine Jm, Janssen Joris H, Spiering Wilko, Kalkman Cor J, van Solinge Wouter W, Dohmen Daan Aj
Department of Anesthesiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.
FocusCura, Driebergen-Rijsenburg, Netherlands.
JMIR Form Res. 2019 Apr 24;3(2):e11489. doi: 10.2196/11489.
Remote monitoring of physical activity in patients with chronic conditions could be useful to offer care professionals real-time assessment of their patient's daily activity pattern to adjust appropriate treatment. However, the validity of commercially available activity trackers that can be used for telemonitoring purposes is limited.
The purpose of this study was to test usability and determine the validity of 3 consumer-level activity trackers as a measure of free-living activity.
A usability evaluation (study 1) and validation study (study 2) were conducted. In study 1, 10 individuals wore one activity tracker for a period of 30 days and filled in a questionnaire on ease of use and wearability. In study 2, we validated three selected activity trackers (Apple Watch, Misfit Shine, and iHealth Edge) and a fourth pedometer (Yamax Digiwalker) against the reference standard (Actigraph GT3X) in 30 healthy participants for 72 hours. Outcome measures were 95% limits of agreement (LoA) and bias (Bland-Altman analysis). Furthermore, median absolute differences (MAD) were calculated. Correction for bias was estimated and validated using leave-one-out cross validation.
Usability evaluation of study 1 showed that iHealth Edge and Apple Watch were more comfortable to wear as compared with the Misfit Flash. Therefore, the Misfit Flash was replaced by Misfit Shine in study 2. During study 2, the total number of steps of the reference standard was 21,527 (interquartile range, IQR 17,475-24,809). Bias and LoA for number of steps from the Apple Watch and iHealth Edge were 968 (IQR -5478 to 7414) and 2021 (IQR -4994 to 9036) steps. For Misfit Shine and Yamax Digiwalker, bias was -1874 and 2004, both with wide LoA of (13,869 to 10,121) and (-10,932 to 14,940) steps, respectively. The Apple Watch noted the smallest MAD of 7.7% with the Actigraph, whereas the Yamax Digiwalker noted the highest MAD (20.3%). After leave-one-out cross validation, accuracy estimates of MAD of the iHealth Edge and Misfit Shine were within acceptable limits with 10.7% and 11.3%, respectively.
Overall, the Apple Watch and iHealth Edge were positively evaluated after wearing. Validity varied widely between devices, with the Apple Watch being the most accurate and Yamax Digiwalker the least accurate for step count in free-living conditions. The iHealth Edge underestimates number of steps but can be considered reliable for activity monitoring after correction for bias. Misfit Shine overestimated number of steps and cannot be considered suitable for step count because of the low agreement. Future studies should focus on the added value of remotely monitoring activity patterns over time in chronic patients.
对慢性病患者的身体活动进行远程监测，有助于医护人员实时评估患者的日常活动模式，从而调整适当的治疗方案。然而，可用于远程监测的市售活动追踪器的有效性有限。
本研究旨在测试3款消费级活动追踪器作为自由生活活动测量工具的可用性，并确定其有效性。
进行了一项可用性评估（研究1）和一项验证研究（研究2）。在研究1中，10名个体佩戴一款活动追踪器30天，并填写一份关于易用性和可穿戴性的问卷。在研究2中，我们在30名健康参与者中，将三款选定的活动追踪器（苹果手表、Misfit Shine和iHealth Edge）以及第四款计步器（Yamax Digiwalker）与参考标准（Actigraph GT3X）进行了72小时的对比验证。结果测量指标为95%一致性界限（LoA）和偏差（Bland-Altman分析）。此外，还计算了中位数绝对差值（MAD）。使用留一法交叉验证对偏差校正进行了估计和验证。
研究1的可用性评估表明，与Misfit Flash相比，iHealth Edge和苹果手表佩戴起来更舒适。因此，在研究2中，Misfit Flash被Misfit Shine取代。在研究2期间，参考标准的总步数为21,527步（四分位间距，IQR 17,475 - 24,809步）。苹果手表和iHealth Edge的步数偏差和LoA分别为968步（IQR -5478至7414步）和2021步（IQR -4994至9036步）。对于Misfit Shine和Yamax Digiwalker，偏差分别为 -1874步和2004步，LoA范围都很宽，分别为（13,869至10,121步）和（-10,932至14,940步）。苹果手表与Actigraph的MAD最小，为7.7%，而Yamax Digiwalker的MAD最高（20.3%）。经过留一法交叉验证后，iHealth Edge和Misfit Shine的MAD准确性估计分别在可接受范围内，为10.7%和11.3%。
总体而言，苹果手表和iHealth Edge在佩戴后得到了积极评价。不同设备之间的有效性差异很大，在自由生活条件下，苹果手表计步最准确，Yamax Digiwalker最不准确。iHealth Edge低估了步数，但在进行偏差校正后可被认为对活动监测可靠。Misfit Shine高估了步数，由于一致性较低，不能被认为适用于计步。未来的研究应关注对慢性病患者长期远程监测活动模式的附加价值。
