Quick Returns - Sleep, Cognitive Functions and Individual Differences

NCT ID: NCT05162105

Last Updated: 2023-08-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 80 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-09-01
• Study Completion Date: 2023-03-10

Brief Summary

The project will contribute with new knowledge concerning how short rest periods between two consecutive shifts (<11h, often defined as a Quick Return (QR)) affects sleep and cognitive performance. The study will further examine whether individual differences in personality traits and genotypes may explain individual differences in performance and sleep. Data will be collected with a randomized cross-over design, in an experimental laboratory setting.

Detailed Description

Rotating shift workers may have a narrow time window to rest after an evening shift, before returning early to work for a day shift. In the literature, a rest opportunity of less than 11 hours between two consecutive shifts, is defined as a Quick Return (QR). Most often, this is occurs when working an evening shift followed by a day shift. Survey- and longitudinal studies have found associations between QRs and an increased risk of being involved in occupational accidents. However, no studies have experimentally investigated how a QR scenario may affect performance at work and sleep between the two shifts. Thus, the project will experimentally simulate QRs, where a battery of cognitive tests will be administered in a laboratory to indicate performance. Objective and subjective sleep will be measured/reported at home where participants normally sleep. Additionally, genotype- and personality trait data will be collected and used as moderators in the analyses.

A randomized cross-over design with two groups will be applied. In one condition, participants will work an evening shift (03:00PM-11:00PM) followed by a day shift (07:00AM-03:00PM, QR). In the other condition, participants work a day shift (07:00AM-03:00PM) followed by another day shift. Four weeks later after being in one of the conditions, the participants will return to the laboratory and work in the opposite condition. Sleep will be subjectively reported with a sleep diary and objectively measured using a low-powered ultra-wideband radar, two days before and between the two simulated shifts in each of the two conditions.

Conditions

Shift Work Schedule; Sleep Deprivation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Evening shift followed by day shift (Quick Return)

Participants work a simulated evening shift, from 03:00PM to 11:00PM, followed by a simulated day shift, 07:00AM to 03:00PM, the following day.

Group Type: EXPERIMENTAL

Short rest (8 hour) between two consecutive shifts.

Intervention Type: OTHER

Participants will have shortened rest opportunity (8 hours) between two consecutive shifts, due to the shift work schedule.

Day shift followed by day shift

Participants work a simulated day shift, from 07:00AM to 03:00PM, followed by another simulated day shift, from 07:00AM to 03:00PM, the following day.

Group Type: ACTIVE_COMPARATOR

16 hour rest opportunity between to consecutive shifts.

Intervention Type: OTHER

Participants will have a 16 hour rest opportunity between shifts, due to shift work schedule.

Interventions

Short rest (8 hour) between two consecutive shifts.

Participants will have shortened rest opportunity (8 hours) between two consecutive shifts, due to the shift work schedule.

Intervention Type: OTHER

16 hour rest opportunity between to consecutive shifts.

Participants will have a 16 hour rest opportunity between shifts, due to shift work schedule.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Participants are physically and mentally healthy (assessed with BMI and 'General Health Questionnaire-12)'.
• Participants accept to comply to the protocol (retain regular bed- and wake times before the simulated shifts).
• Refrain from alcohol and maintain regular nicotine and caffeine usage during participation.
• Norwegian as primary language/proficiency in Norwegian language.

Exclusion Criteria

• Neurological, psychiatric or sleep related disorders ('Bergen Insomnia Scale, 'Global sleep assessment questionnaire').
• Extreme 'morning-eveningness' type ('Horne-Östberg).
• Use of medication that affect sleep or cognitive performance.
• Pregnancy.

• Minimum Eligible Age: 19 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Bergen

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

University of Bergen, Department of Psychosocial Science

Bergen, , Norway

Countries

Norway

References

Holmelid O, Harris A, Pallesen S, Bjorvatn B, Vedaa O, Waage S, Nielsen MB, Djupedal ILR, Sunde E. Acute effects of a simulated quick return on subjective sleepiness, mood, and cognitive performance: A laboratory crossover controlled trial. Chronobiol Int. 2024 Aug;41(8):1116-1127. doi: 10.1080/07420528.2024.2380736. Epub 2024 Jul 22.

Reference Type: DERIVED

PMID: 39037118 (View on PubMed)

Other Identifiers

303671

Identifier Type: -

Identifier Source: org_study_id