Comparison of Wearable Activity Tracker with Actigraphy for Sleep Evaluation and Circadian Rest-Activity Rhythm Measurement in Healthy Young Adults.
OBJECTIVE
The purpose of this study was to evaluate the applicability of data obtained from a wearable activity tracker (Fitbit Charge HR) to medical research. This was performed by comparing the wearable activity tracker (Fitbit Charge HR) with actigraphy (Actiwatch 2) for sleep evaluation and circadian rest-activity rhythm measurement.


METHODS
Sixteen healthy young adults (female participants, 62.5%; mean age, 22.8 years) wore the Fitbit Charge HR and the Actiwatch 2 on the same wrist; a sleep log was recorded over a 14-day period. We compared the sleep variables and circadian rest-activity rhythm measures with Wilcoxon signed-rank tests and Spearman's correlations.


RESULTS
The periods and acrophases of the circadian rest-activity rhythms and the sleep start times did not differ and correlated significantly between the Fitbit Charge HR and the Actiwatch 2. The Fitbit Charge HR tended to overestimate the sleep durations compared with the Actiwatch 2. However, the sleep durations showed high correlation between the two devices for all days.


CONCLUSIONS
We found that the Fitbit Charge HR showed high accuracy in sleep evaluation and circadian rest-activity rhythm measurement when compared with actigraphy for healthy young adults. The results suggest that the Fitbit Charge HR could be applicable on medical research as an alternative tool to actigraphy for sleep evaluation and measurement of the circadian rest-activity rhythm.
Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea.
Hyun-Ah
HA
Lee
Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea.; Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Republic of Korea.
Heon-Jeong
HJ
Lee
Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Republic of Korea.
Joung-Ho
JH
Moon
Department of Computer Science, Korea University College of Information and Communications, Seoul, Republic of Korea.
Taek
T
Lee
Department of Computer Science, Korea University College of Information and Communications, Seoul, Republic of Korea.
Min-Gwan
MG
Kim
Department of Computer Science, Korea University College of Information and Communications, Seoul, Republic of Korea.
Hoh
H
In
Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea.
Chul-Hyun
CH
Cho
Department of Psychiatry, Korea University College of Medicine, Seoul, Republic of Korea.
Leen
L
Kim
Actigraphy; Circadian rest-activity rhythm; Comparison; Sleep; Wearable activity tracker