Assessment of Stress and Well-Being of Japanese Employees Using Wearable Devices for Sleep Monitoring Combined With Ecological Momentary Assessment: Pilot Observational Study

Shotaro Kinoshita; Sayaka Hanashiro; Shiori Tsutsumi; Kiko Shiga; Momoko Kitazawa; Yasuyo Wada; Jun Inaishi; Kazuhiro Kashiwagi; Toshikazu Fukami; Yasumasa Mashimo; Kazumichi Minato; Taishiro Kishimoto

doi:10.2196/49396

Assessment of Stress and Well-Being of Japanese Employees Using Wearable Devices for Sleep Monitoring Combined With Ecological Momentary Assessment: Pilot Observational Study

JMIR Form Res. 2024 May 2:8:e49396. doi: 10.2196/49396.

Authors

Shotaro Kinoshita^{1

2}, Sayaka Hanashiro³, Shiori Tsutsumi⁴, Kiko Shiga^{3

5}, Momoko Kitazawa³, Yasuyo Wada^{6

7}, Jun Inaishi^{6

8}, Kazuhiro Kashiwagi^{1

6}, Toshikazu Fukami⁹, Yasumasa Mashimo⁹, Kazumichi Minato⁹, Taishiro Kishimoto^{1

10

11

12}

Affiliations

¹ Hills Joint Research Laboratory for Future Preventive Medicine and Wellness, Keio University School of Medicine, Tokyo, Japan.
² Graduate School of Interdisciplinary Information Studies, The University of Tokyo, Tokyo, Japan.
³ Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan.
⁴ Graduate School of Health Management, Keio University, Kanagawa, Japan.
⁵ Department of Clinical Psychology, Faculty of Human Relations, Shigakukan University, Kagoshima, Japan.
⁶ Center for Preventice Medicine, Keio University Hospital, Tokyo, Japan.
⁷ Department of Health Promotion, National Institute of Public Health, Saitama, Japan.
⁸ Division of Endocrinology, Metabolism and Nephrology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
⁹ TechDoctor, Inc., Tokyo, Japan.
¹⁰ Department of Psychiatry, The Zucker Hillside Hospital, Northwell Health, New York, NY, United States.
¹¹ Department of Psychiatry, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States.
¹² Department of Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States.

PMID: 38696237
PMCID: PMC11099815
DOI: 10.2196/49396

Abstract

Background: Poor sleep quality can elevate stress levels and diminish overall well-being. Japanese individuals often experience sleep deprivation, and workers have high levels of stress. Nevertheless, research examining the connection between objective sleep assessments and stress levels, as well as overall well-being, among Japanese workers is lacking.

Objective: This study aims to investigate the correlation between physiological data, including sleep duration and heart rate variability (HRV), objectively measured through wearable devices, and 3 states (sleepiness, mood, and energy) assessed through ecological momentary assessment (EMA) and use of rating scales for stress and well-being.

Methods: A total of 40 office workers (female, 20/40, 50%; mean age 40.4 years, SD 11.8 years) participated in the study. Participants were asked to wear a wearable wristband device for 8 consecutive weeks. EMA regarding sleepiness, mood, and energy levels was conducted via email messages sent by participants 4 times daily, with each session spaced 3 hours apart. This assessment occurred on 8 designated days within the 8-week timeframe. Participants' stress levels and perception of well-being were assessed using respective self-rating questionnaires. Subsequently, participants were categorized into quartiles based on their stress and well-being scores, and the sleep patterns and HRV indices recorded by the Fitbit Inspire 2 were compared among these groups. The Mann-Whitney U test was used to assess differences between the quartiles, with adjustments made for multiple comparisons using the Bonferroni correction. Furthermore, EMA results and the sleep and HRV indices were subjected to multilevel analysis for a comprehensive evaluation.

Results: The EMA achieved a total response rate of 87.3%, while the Fitbit Inspire 2 wear rate reached 88.0%. When participants were grouped based on quartiles of well-being and stress-related scores, significant differences emerged. Specifically, individuals in the lowest stress quartile or highest subjective satisfaction quartile retired to bed earlier (P<.001 and P=.01, respectively), whereas those in the highest stress quartile exhibited greater variation in the midpoint of sleep (P<.001). A multilevel analysis unveiled notable relationships: intraindividual variability analysis indicated that higher energy levels were associated with lower deviation of heart rate during sleep on the preceding day (β=-.12, P<.001), and decreased sleepiness was observed on days following longer sleep durations (β=-.10, P<.001). Furthermore, interindividual variability analysis revealed that individuals with earlier midpoints of sleep tended to exhibit higher energy levels (β=-.26, P=.04).

Conclusions: Increased sleep variabilities, characterized by unstable bedtime or midpoint of sleep, were correlated with elevated stress levels and diminished well-being. Conversely, improved sleep indices (eg, lower heart rate during sleep and earlier average bedtime) were associated with heightened daytime energy levels. Further research with a larger sample size using these methodologies, particularly focusing on specific phenomena such as social jet lag, has the potential to yield valuable insights.

Trial registration: UMIN-CTR UMIN000046858; https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053392.

Keywords: ecological momentary assessment; feasibility study; sleep feedback; stress; wearable device; well-being.

©Shotaro Kinoshita, Sayaka Hanashiro, Shiori Tsutsumi, Kiko Shiga, Momoko Kitazawa, Yasuyo Wada, Jun Inaishi, Kazuhiro Kashiwagi, Toshikazu Fukami, Yasumasa Mashimo, Kazumichi Minato, Taishiro Kishimoto. Originally published in JMIR Formative Research (https://formative.jmir.org), 02.05.2024.