Chowdhury Enhad A, Western Max J, Nightingale Thomas E, Peacock Oliver J, Thompson Dylan
Department for Health, University of Bath, Bath, United Kingdom.
PLoS One. 2017 Feb 24;12(2):e0171720. doi: 10.1371/journal.pone.0171720. eCollection 2017.
Wearable physical activity monitors are growing in popularity and provide the opportunity for large numbers of the public to self-monitor physical activity behaviours. The latest generation of these devices feature multiple sensors, ostensibly similar or even superior to advanced research instruments. However, little is known about the accuracy of their energy expenditure estimates. Here, we assessed their performance against criterion measurements in both controlled laboratory conditions (simulated activities of daily living and structured exercise) and over a 24 hour period in free-living conditions. Thirty men (n = 15) and women (n = 15) wore three multi-sensor consumer monitors (Microsoft Band, Apple Watch and Fitbit Charge HR), an accelerometry-only device as a comparison (Jawbone UP24) and validated research-grade multi-sensor devices (BodyMedia Core and individually calibrated Actiheart™). During discrete laboratory activities when compared against indirect calorimetry, the Apple Watch performed similarly to criterion measures. The Fitbit Charge HR was less consistent at measurement of discrete activities, but produced similar free-living estimates to the Apple Watch. Both these devices underestimated free-living energy expenditure (-394 kcal/d and -405 kcal/d, respectively; P<0.01). The multi-sensor Microsoft Band and accelerometry-only Jawbone UP24 devices underestimated most laboratory activities and substantially underestimated free-living expenditure (-1128 kcal/d and -998 kcal/d, respectively; P<0.01). None of the consumer devices were deemed equivalent to the reference method for daily energy expenditure. For all devices, there was a tendency for negative bias with greater daily energy expenditure. No consumer monitors performed as well as the research-grade devices although in some (but not all) cases, estimates were close to criterion measurements. Thus, whilst industry-led innovation has improved the accuracy of consumer monitors, these devices are not yet equivalent to the best research-grade devices or indeed equivalent to each other. We propose independent quality standards and/or accuracy ratings for consumer devices are required.
可穿戴式身体活动监测器越来越受欢迎，为大量公众提供了自我监测身体活动行为的机会。这些设备的最新一代配备了多个传感器，表面上类似于甚至优于先进的研究仪器。然而，人们对其能量消耗估计的准确性知之甚少。在这里，我们在受控实验室条件（模拟日常生活活动和结构化锻炼）以及自由生活条件下的24小时内，根据标准测量评估了它们的性能。30名男性（n = 15）和女性（n = 15）佩戴了三款多传感器消费级监测器（微软手环、苹果手表和Fitbit Charge HR）、一款仅用于加速计测量的设备作为对照（Jawbone UP24）以及经过验证的研究级多传感器设备（BodyMedia Core和单独校准的Actiheart™）。在离散实验室活动期间，与间接量热法相比时，苹果手表的表现与标准测量相似。Fitbit Charge HR在离散活动测量方面不太一致，但在自由生活状态下的估计与苹果手表相似。这两款设备都低估了自由生活状态下的能量消耗（分别为-394千卡/天和-405千卡/天；P<0.01）。多传感器微软手环和仅用于加速计测量的Jawbone UP24设备低估了大多数实验室活动，并且大幅低估了自由生活状态下的能量消耗（分别为-1128千卡/天和-998千卡/天；P<0.01）。没有一款消费级设备被认为等同于日常能量消耗的参考方法。对于所有设备，随着每日能量消耗增加，存在负偏差的趋势。没有一款消费级监测器的表现与研究级设备一样好，尽管在某些（但不是所有）情况下，估计值接近标准测量。因此，虽然行业主导的创新提高了消费级监测器的准确性，但这些设备尚未等同于最佳研究级设备，甚至彼此之间也不等同。我们建议需要为消费级设备制定独立的质量标准和/或准确性评级。
