Association between chronotype and sleep/fatigue indicators among shift workers

A pilot study to determine how chronotypes relate to sleep, fatigue recovery, and presenteeism during the night shift among shift workers

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

JPRN

Registry ID

JPRN-jRCT1040240012

Enrollment

Registered

2024-04-10

Start date

2023-10-22

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Sleep disorders, insufficient recovery from fatigue and presenteeism among shift worker

Interventions

None listed

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: Male adult workers who belonged to a company cooperating in the survey and had worked in shift work for at least one month.

Exclusion criteria

Exclusion criteria: Within 1 month after entering or returning to work, under treatment for sleep disorders or mental illness, female, age under 20 and over 50

Design outcomes

Primary

Measure	Time frame
Objective sleep index (sleep efficiency) by chronotype	—

Secondary

Measure	Time frame
Objective sleep indices: total sleep duration, duration of awakenings Subjective sleep indices: sleep depth, number of wake after onset, sleep satisfaction Objective fatigue index: oxidative stress value, antioxidant capacity, modification ratio Subjective fatigue index: Fatigue visual analogue scale Presenteeism (SPQ) Mental health (K6)	—

Contacts

Public ContactMakoto Kageyama

Hamamatsu University School of Medicine

m.kage@hama-med.ac.jp+81-53-435-2834

Outcome results