Precision Health, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Clinical Sciences, Lund University, Skåne University Hospital, Malmö, Sweden; School of Health Innovation, Kanagawa University of Human Services Graduate School, Research Gate Building Tonomachi 2-A 2, 3F, 3-25-10 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, Japan.
Precision Health, Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; School of Health Innovation, Kanagawa University of Human Services Graduate School, Research Gate Building Tonomachi 2-A 2, 3F, 3-25-10 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, Japan; Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
J Psychosom Res. 2019 Nov;126:109822. doi: 10.1016/j.jpsychores.2019.109822. Epub 2019 Aug 30.
To compare a wearable device, the Fitbit Versa (FV), to a validated portable single-channel EEG system across multiple nights in a naturalistic environment.
Twenty participants (10 men and 10 women) aged 25-67 years were recruited for the present study. Study duration was 14 days during which participants were asked to wear the FV daily and nightly. The study intended to reproduce free-living conditions; thus, no guidelines for sleep or activity were imposed on the participants. A total of 138 person-nights, equivalent to 76,539 epochs, were used in the validation process. Sleep measures were compared between the FV and portable EEG using Bland-Altman plots, paired t-tests and epoch-by-epoch (EBE) analyses.
The FV showed no significant bias with the EEG for the global sleep measures time in bed (TIB) and total sleep time (TST), and for calculated sleep efficiency (cSE = [TST/TIB] x 100). The FV had 92.1% sensitivity, 54.1% specificity, and 88.5% accuracy with a Cohen's kappa of 0.41, but a prevalence- and bias adjusted kappa of 0.77. The predictive values for sleep (PVS; positive predictive value) and wakefulness (PVW; negative predictive value) were 95.0% and 42.0%, respectively. The FV showed significant bias compared to the portable EEG for time spent in specific sleep stages, for SE as provided by FV, for sleep onset latency, sleep period time, and wake after sleep onset.
The consumer sleep tracker could be a useful tool for measuring sleep duration in longitudinal epidemiologic naturalistic studies albeit with some limitations in specificity.
将可穿戴设备 Fitbit Versa（FV）与经过验证的便携式单通道 EEG 系统在自然环境下的多个夜晚进行比较。
本研究招募了 20 名年龄在 25-67 岁的参与者（10 名男性和 10 名女性）。研究持续了 14 天，在此期间，参与者被要求每天和每晚佩戴 FV。该研究旨在再现自由生活条件；因此，没有向参与者提出关于睡眠或活动的指导方针。在验证过程中，共使用了 138 个人夜，相当于 76539 个epoch。睡眠测量值使用 Bland-Altman 图、配对 t 检验和逐 epoch（EBE）分析，将 FV 与便携式 EEG 进行比较。
FV 在全局睡眠测量值（TIB 和 TST）和计算的睡眠效率（cSE=[TST/TIB]×100）方面与 EEG 无显著偏差。FV 的灵敏度为 92.1%，特异性为 54.1%，准确度为 88.5%，Cohen's kappa 值为 0.41，但经患病率和偏差调整后的 kappa 值为 0.77。睡眠的预测值（PVS；阳性预测值）和觉醒的预测值（PVW；阴性预测值）分别为 95.0%和 42.0%。FV 在特定睡眠阶段的睡眠时间、FV 提供的 SE、睡眠潜伏期、睡眠周期时间和睡眠后觉醒时间等方面与便携式 EEG 存在显著偏差。
尽管在特异性方面存在一些限制，但消费级睡眠追踪器可以成为测量纵向流行病学自然主义研究中睡眠持续时间的有用工具。
