TY - JOUR
T1 - A validation study of a consumer wearable sleep tracker compared to a portable EEG system in naturalistic conditions
AU - Svensson, Thomas
AU - Chung, Ung il
AU - Tokuno, Shinichi
AU - Nakamura, Mitsuteru
AU - Svensson, Akiko Kishi
N1 - Funding Information:
This research was supported by the Center of Innovation Program from Japan Science and Technology Agency, JST. We thank all staff members at the Center of Innovation, the University of Tokyo for their extensive efforts and help to conduct the study. We would also like to thank all members of Precision Health, the University of Tokyo for their invaluable assistance, in particular Fumiya Tatsuki and Ei Hiruma for their help with protocol writing and data extraction, respectively. Thomas Svensson had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Funding Information:
This research was supported by the Center of Innovation Program from Japan Science and Technology Agency , JST.
Publisher Copyright:
© 2019 Elsevier Inc.
PY - 2019/11
Y1 - 2019/11
N2 - Objective: To compare a wearable device, the Fitbit Versa (FV), to a validated portable single-channel EEG system across multiple nights in a naturalistic environment. Methods: 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. Results: 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. Conclusions: The consumer sleep tracker could be a useful tool for measuring sleep duration in longitudinal epidemiologic naturalistic studies albeit with some limitations in specificity.
AB - Objective: To compare a wearable device, the Fitbit Versa (FV), to a validated portable single-channel EEG system across multiple nights in a naturalistic environment. Methods: 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. Results: 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. Conclusions: The consumer sleep tracker could be a useful tool for measuring sleep duration in longitudinal epidemiologic naturalistic studies albeit with some limitations in specificity.
KW - Portable EEG
KW - Sleep duration
KW - Sleep measures
KW - Sleep tracking
KW - Validation study
KW - Wearable device
UR - http://www.scopus.com/inward/record.url?scp=85071835571&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85071835571&partnerID=8YFLogxK
U2 - 10.1016/j.jpsychores.2019.109822
DO - 10.1016/j.jpsychores.2019.109822
M3 - Article
C2 - 31499232
AN - SCOPUS:85071835571
VL - 126
JO - Journal of Psychosomatic Research
JF - Journal of Psychosomatic Research
SN - 0022-3999
M1 - 109822
ER -