Clinical trial NCT05162105: Quick Returns - Sleep, Cognitive Functions and Individual Differences
Official title: Quick Returns - Sleep, Cognitive Functions and Individual Differences: An Experimental Approach
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Shift Work Schedule
Sleep Deprivation
Keywords: Shift Work
Quick Return
Sleep
Cognitive Performance
Circadian Rhythm
Genotype
Shift Work Tolerance
Lead sponsor: University of Bergen
Sponsor class: OTHER
First posted: 2021-12-17
Enrollment: 80
Sex: ALL
Minimum age (years): 19
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: 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.
Primary purpose: TREATMENT

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.

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.

Primary outcomes:
measure: Sustained Attention
timeFrame: 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.
measure: Sleepiness
timeFrame: 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.
measure: Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Onset Latency'
timeFrame: 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).
measure: Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Total Sleep Time'
timeFrame: 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).
measure: 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'
timeFrame: 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).
measure: 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'
timeFrame: 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).
measure: 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'
timeFrame: 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:
measure: Mood/Affect
timeFrame: 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.
measure: Moral Decision
timeFrame: 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.
measure: Change in Cognitive Throughput
timeFrame: 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.
measure: Selective Attention
timeFrame: 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.
measure: Executive functioning
timeFrame: 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.
measure: Dexterity
timeFrame: 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.
measure: Verbal Memory
timeFrame: 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.
measure: Cognitive Inhibition
timeFrame: 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.
measure: Individual Differences - Mini International Personality Item Pool (Mini-IPIP)
timeFrame: Pre-intervention
measure: Individual Differences - Dark Triad Personality Scale
timeFrame: Pre-intervention
measure: Individual Differences - Revised Circadian Type Inventory (CTI-R)
timeFrame: Pre-intervention
measure: Individual Differences - Horne-Östberg Morning-Eveningness Questionnaire (MEQ)
timeFrame: Pre-intervention
measure: Individual Differences - Genotypes
timeFrame: Pre-intervention
measure: Arousal prior to bedtime - one night between two day shifts versus one night between evening- followed by day shift
timeFrame: Prior to bedtime the night between the two shifts in the QR condition (from 11PM-7AM) compared to the night between two shifts in the control condition (from 3PM-7AM).
measure: Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Quality'
timeFrame: 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).
measure: Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Wake After Sleep Onset'
timeFrame: 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).
measure: Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Efficiency'
timeFrame: 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).
measure: Subjective Sleep,one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Onset Latency'
timeFrame: 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).
measure: Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Bedtime'
timeFrame: 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).
measure: Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Wake after sleep onset'
timeFrame: 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).
measure: Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Efficiency'
timeFrame: 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).
measure: Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Bedtime'
timeFrame: 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).
measure: Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Total Sleep Time'
timeFrame: 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).
Other outcomes:
Locations:
city: Bergen
country: Norway
facility: University of Bergen, Department of Psychosocial Science
Study officials:
References: