Quick Returns - Sleep, Cognitive Functions and Individual Differences

NCT05162105 | Completed

• 1 other identifier: 303671
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

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.

Conditions

Shift Work Schedule; Sleep Deprivation

Keywords

Shift Work; Quick Return; Sleep; Cognitive Performance; Circadian Rhythm; Genotype; Shift Work Tolerance

Outcome Measures

Primary Outcomes (7)

• Sustained Attention

  Sustained attention will be measured using the Psychomotor Vigilance Test (PVT). The PVT is a commonly used test to assess the effect of sleep deprivation on cognitive functioning. The test will be conducted every 1.5h - 2h during simulated shifts, in total five times during the day shift (07:30AM, 09:00AM,10:30AM, 12:30PM and 02:30PM) and five times during the evening shift (03:30PM, 05:00PM, 6:30PM, 8:30PM and 10:30PM).

  Changes from first to last test session on day 2, in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2, in the control condition (day- followed by day shift). Day 2 both combinations: 7AM-3PM.

• Sleepiness

  The Karolinska Sleepiness Scale (KSS) is a single item question measuring sleepiness on a likert scale from 1 - 9 ('1' - "Extremely alert" to '9' - "Very sleepy/fighting sleep"). The test will be conducted every 1.5h - 2h during simulated shifts, in total five times during the day shift (07:30AM, 09:00AM,10:30AM, 12:30PM and 02:30PM) and five times during the evening shift (03:30PM, 05:00PM, 6:30PM, 8:30PM and 10:30PM).

  Changes from first to last test session on day 2, in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2, in the control condition (day- followed by day shift). Day 2 both combinations: 7AM-3PM.

• Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Onset Latency'

  To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'sleep onset latency' will be objectively measured using a low-powered ultra -wideband Xethru sleep radar (Somnofy), placed next to the bed. Sleep opportunity will in the QR-condition be between 11PM-7AM and in the control-condition between 3PM-7AM, as a consequence of simulated shift schedule (QR-condition; first shift on day 1 occurring 3PM-11PM \& second shift on day 2 occurring 7AM-3PM. Control-condition; first shift on day 1 occurring 7AM-3PM \& second shift on day 2 occurring 7AM-3PM the following day). Sleep Onset Latency in the two sleep opportunities will be compared.

  Sleep taking place between the two days in the QR condition (from 11PM-7AM) compared to sleep taking place between the two days in the control condition (from 3PM-7AM).

• Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Total Sleep Time'

  To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'total sleep time' will be objectively measured using a low-powered ultra -wideband Xethru sleep radar (Somnofy). Sleep opportunity will in the QR-condition be between 11PM-7AM and in the control-condition between 3PM-7AM, as a consequence of simulated shift schedule (QR-condition; first shift on day 1 occurring 3PM-11PM \& second shift on day 2 occurring 7AM-3PM. Control-condition; first shift on day 1 occurring 7AM-3PM \& second shift on day 2 occurring 7AM-3PM the following day). Total Sleep Time in the two sleep opportunities will be compared.

  Sleep taking place between the two days in the QR condition (from 11PM-7AM) compared to sleep taking place between the two days in the control condition (from 3PM-7AM).

• Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Time in Light Sleep'

  To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'time in light sleep' will be objectively measured using a low-powered ultra -wideband Xethru sleep radar (Somnofy), placed next to the bed. Sleep opportunity will in the QR-condition be between 11PM-7AM and in the control-condition between 3PM-7AM, as a consequence of simulated shift schedule (QR-condition; first shift on day 1 occurring 3PM-11PM \& second shift on day 2 occurring 7AM-3PM. Control-condition; first shift on day 1 occurring 7AM-3PM \& second shift on day 2 occurring 7AM-3PM the following day). Time in Light Sleep in the two sleep opportunities will be compared.

  Sleep taking place between the two days in the QR condition (from 11PM-7AM) compared to sleep taking place between the two days in the control condition (from 3PM-7AM).

• Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Time in Deep Sleep'

  To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'time in deep sleep' will be objectively measured using a low-powered ultra -wideband Xethru sleep radar (Somnofy), placed next to the bed. Sleep opportunity will in the QR-condition be between 11PM-7AM and in the control-condition between 3PM-7AM, as a consequence of simulated shift schedule (QR-condition; first shift on day 1 occurring 3PM-11PM \& second shift on day 2 occurring 7AM-3PM. Control-condition; first shift on day 1 occurring 7AM-3PM \& second shift on day 2 occurring 7AM-3PM the following day). Time in Deep Sleep in the two sleep opportunities will be compared.

  Sleep taking place between the two days in the QR condition (from 11PM-7AM) compared to sleep taking place between the two days in the control condition (from 3PM-7AM).

• Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Time in Rapid Eye Movement(REM)-sleep'

  To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'time in REM-sleep' will be objectively measured using a low-powered ultra -wideband Xethru sleep radar (Somnofy), placed next to the bed. Sleep opportunity will in the QR-condition be between 11PM-7AM and in the control-condition between 3PM-7AM, as a consequence of simulated shift schedule (QR-condition; first shift on day 1 occurring 3PM-11PM \& second shift on day 2 occurring 7AM-3PM. Control-condition; first shift on day 1 occurring 7AM-3PM \& second shift on day 2 occurring 7AM-3PM the following day). Time in Rapid Eye Movement(REM)-sleep in the two sleep opportunities will be compared.

  Sleep taking place between the two days in the QR condition (from 11PM-7AM) compared to sleep taking place between the two days in the control condition (from 3PM-7AM).

Secondary Outcomes (23)

• Mood/Affect

  Changes from first to last test session on day 2, in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2, in the control condition (day- followed by day shift). Day 2 both combinations: 7AM-3PM.

• Moral Decision

  Difference between day 2, in simulated QR (evening- followed by day shift) and day 2 in the control condition (day- followed by day shift). Day 2 in QR- and control combination: 7AM-3PM.

• Change in Cognitive Throughput

  Changes from first to last test session on day 2 in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2 in the control condition (day- followed by day shift). Day 2 in QR- and control combination: 7AM-3PM.

• Selective Attention

  Changes from first to last test session on day 2, in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2, in the control condition (day- followed by day shift). Day 2 both combinations: 7AM-3PM.

• Executive functioning

  Changes from first to last test session on day 2, in a simulated QR (evening- followed by day shift) and changes from first to last test session on day 2, in the control condition (day- followed by day shift). Day 2 both combinations: 7AM-3PM.

Study Arms (2)

Evening shift followed by day shift (Quick Return)

EXPERIMENTAL

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.

Other: Short rest (8 hour) between two consecutive shifts.

Day shift followed by day shift

ACTIVE COMPARATOR

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.

Other: 16 hour rest opportunity between to consecutive shifts.

Interventions

Short rest (8 hour) between two consecutive shifts. OTHER

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

Evening shift followed by day shift (Quick Return)

16 hour rest opportunity between to consecutive shifts. OTHER

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

Day shift followed by day shift

Eligibility Criteria

• Age: 19 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Bergen: lead

Study Sites (1)

University of Bergen, Department of Psychosocial Science

Bergen, Norway

Location

Related Publications (1)

• 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.

  PMID: 39037118 DERIVED

MeSH Terms

Conditions

Sleep Deprivation

Condition Hierarchy (Ancestors)

Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Mental Disorders

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants will not be provided information regarding hypotheses or expected results from the different conditions.
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants are randomly assigned to the QR-condition (evening shift followed by a day shift) or a day shift followed by another day shift. After a four week wash-out, participants return to work in the opposite condition.

Study Record Dates

• First Submitted: August 30, 2021
• First Posted: December 17, 2021
• Study Start: September 1, 2021
• Primary Completion: March 10, 2023
• Study Completion: March 10, 2023
• Last Updated: August 22, 2023

Record last verified: 2023-08

Data Sharing

• IPD Sharing: Will not share

Locations

NO (1)