Shift Work ScheduleNCT05162105
Quick Returns - Sleep, Cognitive Functions and Individual Differences
A study testing Short rest (8 hour) between two consecutive shifts. and 16 hour rest opportunity between to consecutive shifts. in people with Shift Work Schedule and Sleep Deprivation, run by University of Bergen at 1 site in Norway.
Trial 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. Read more about this study
- Who is it for?
- Ages 19 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Shift Work Schedule, Sleep Deprivation
- What is being tested?
- Short rest (8 hour) between two consecutive shifts. and 16 hour rest opportunity between to consecutive shifts.
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteNorway
- Study dates
- 1 Sep 2021to 10 Mar 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Quick Returns - Sleep, Cognitive Functions and Individual Differences: An Experimental Approach
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.
Read the 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
- Being tested
- Short rest (8 hour) between two consecutive shifts., 16 hour rest opportunity between to consecutive shifts.
- Keywords
- Shift Work, Quick Return, Sleep, Cognitive Performance, Circadian Rhythm, Genotype, Shift Work Tolerance
- Medical subject headings
- Sleep Deprivation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
16 hour rest opportunity between to consecutive shifts.Other
Participants will have a 16 hour rest opportunity between shifts, due to shift work schedule.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: Other: 16 hour rest opportunity between to consecutive shifts. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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).
Measured: 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).
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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
Mood/affect is measured using the Positive and Negative Affect Scale (PANAS). PANAS contains 20 items. Each item is rated on a likert scale from 1 to 5 ('1' - None" and '5' - Extremely"). 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).
Measured: 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
The Defining Issue Test (DIT-2) will be used to evaluate the effect of simulated short rest between two shifts (QR) on morality (decision making). DIT-2 presents five moral dilemmas where participants rate and rank issues surrounding the dilemmas on a likert scale from 1 to 5 ('1' - "Very important" to '5' - "Very little important"). Will be completed once at the start of each shift.
Measured: 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
Cognitive throughput will be measured using the 'digit symbol substitution task'. Taken throughout the shifts every 1.5h - 2h in total 5 times during each 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).
Measured: 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
Selective attention will be measured using a 'visual search task'. The test will be taken twice per simulated shift; once during first half and once during second half of the shift.
Measured: 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
Executive functioning will be measured using the 'attentional network task'. The test will be taken twice per simulated shift; once during first half and once during second half of the shift.
Measured: 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.
Dexterity
Dexterity will be measured using the 'grooved pegboard test'. The test will be taken twice per simulated shift; once during first half and once during second half of the shift.
Measured: 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.
Verbal Memory
Verbal memory will be measured using a 'word probe recall test'. The test will be taken twice per simulated shift; once during first half and once during second half of the shift.
Measured: 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.
Cognitive Inhibition
Cognitive inhibition will be measured using the 'go/no-go' test. The test will be taken twice per simulated shift; once during first half and once during second half of the shift.
Measured: 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.
Individual Differences - Mini International Personality Item Pool (Mini-IPIP)
To examine if individual differences can moderate a potential effect of short rest between two shifts, Mini IPIP will be used. Mini-IPIP is a 20-item short form of the 50-item International Personality Item Pool-Five Factor Model. Scores participant on five dimensions: neuroticism, extraversion, agreeableness, conscientiousness, and openness based on a set of likert-scale questions from 1 - 5 ('1' - "Very incorrect" to '5' - "Very correct").
Measured: Pre-intervention
Individual Differences - Dark Triad Personality Scale
To examine if individual differences can moderate a potential effect of short rest between two shifts, the Dark Triad Personality scale will be used. Dark Triad Personality Scale contains 12-items. The test scores the participant based on a set of likert-scale questions from 1 - 9 ('1'- "Completely disagree" to '9' "Completely agree") on the dimensions; machiavellianism, narcissism and psychopathy.
Measured: Pre-intervention
Individual Differences - Revised Circadian Type Inventory (CTI-R)
To examine if individual differences can moderate a potential effect of short rest between two shifts, the CTI-R will be used. CTI-R contains 11-items indicating ability to change sleeping rhythm based on the dimensions; flexibility and languidity. The test scores the participant on based on a set of likert-scale questions from 1 - 5 ('1' - "Almost never" to '5' - "Almost always"). High scores on flexibility reflect better ability to sleep and work at odd times, whereas high scores on languidity indicates difficulties overcoming drowsiness and feeling of lethargy following sleep loss.
Measured: Pre-intervention
Individual Differences - Horne-Östberg Morning-Eveningness Questionnaire (MEQ)
To examine if individual differences can moderate a potential effect of short rest between two shifts, the MEQ will be used. MEQ contains 19-items indicating circadian preference; morning-/evening type.
Measured: Pre-intervention
Individual Differences - Genotypes
To examine if individual differences can moderate a potential effect of short rest between two shifts, saliva samples will be collected to analyze for genotypes related to shift work tolerance.
Genotyping will be done with regard to: SLC6A4 tandem repeat length in the promoter (short; S versus long; L), rs25531 (A versus G), rs8192440, rs12506228 and rs4680. Analyses will be done using Custom TaqMan genotyping assays.
Measured: Pre-intervention
Arousal prior to bedtime - one night between two day shifts versus one night between evening- followed by day shift
Pre-Sleep Arousal Scale (PSAS) will be used to examine if participants differ in arousal-level at bedtime in the two sleep opportunities. PSAS contains 16 items, each being rated on a 5-point likert scale from 1 to 5 ('1' - "Not at all" to '5' - "Extremely"). 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). Arousal at bedtime in the two sleep opportunities in each condition will between will be compared.
Measured: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Quality'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'sleep quality' is reported in a sleep diary. 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 quality in the two sleep opportunities will be compared.
Measured: 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).
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'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'wake after sleep onset' is reported in a sleep diary. 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). Wake after sleep onset in the two sleep opportunities will be compared.
Measured: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Efficiency'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'sleep efficiency' is reported in a sleep diary. 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 efficiency in the two sleep opportunities will be compared.
Measured: 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).
Subjective 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' is reported in a sleep diary. 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.
Measured: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Bedtime'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'bedtime' is reported in a sleep diary. 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). Bedtime in the two sleep opportunities between will be compared.
Measured: 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 - 'Wake after sleep onset'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'wake after sleep onset' 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). Wake after sleep onset in the two sleep opportunities will be compared.
Measured: 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 - 'Sleep Efficiency'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'sleep efficiency' 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 Efficiency in the two sleep opportunities will be compared.
Measured: 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 - 'Bedtime'
To evaluate the effect of simulated short rest between two shifts (QR) on sleep, 'bedtime' 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). Bedtime in the two sleep opportunities will be compared.
Measured: 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).
Subjective 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' is reported in a sleep diary. 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.
Measured: 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).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Dec 2021
- Study start1 Sep 2021
- Primary completion10 Mar 2023
- Study completion10 Mar 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Shift Work ScheduleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- 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.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Bergen
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05162105
- Sponsor's protocol ID
- 303671
- Status last verified
- Aug 2023
- First submitted
- 30 Aug 2021
- Last updated
- 22 Aug 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: After the project has ended the data will be anonymized and no direct recognizable information will be stored.
Publications
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.
PubMed 39037118
Study at a glance
From the registry record, last updated by the sponsor on 22 Aug 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Quick Returns - Sleep, Cognitive Functions and Individual Differences: An Experimental Approach
- ClinicalTrials.gov ID
- NCT05162105
- Acronym / sponsor ID
- 303671
- Conditions
- Shift Work Schedule, Sleep Deprivation
- Keywords
- Shift Work, Quick Return, Sleep, Cognitive Performance, Circadian Rhythm, Genotype, Shift Work Tolerance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- University of BergenUniversity, hospital or other
- Study start
- 1 Sep 2021 (actual)
- Primary completion
- 10 Mar 2023 (actual)
- Study completion
- 10 Mar 2023 (actual)
- First posted
- 17 Dec 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
- 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.
| Arm | Type | Receives |
|---|---|---|
| Evening shift followed by day shift (Quick Return) | Experimental | Other: Short rest (8 hour) between two consecutive shifts.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. |
| Day shift followed by day shift | Active comparator | Other: 16 hour rest opportunity between to consecutive shifts.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. |
Who may qualify
- Ages
- 19 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (4 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 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. | Other | Evening shift followed by day shift (Quick Return) |
| 16 hour rest opportunity between to consecutive shifts.Participants will have a 16 hour rest opportunity between shifts, due to shift work schedule. | Other | Day shift followed by day shift |
Primary outcome
Sustained Attention
Time frame: 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.
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).
Sleepiness
Time frame: 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.
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).
Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Onset Latency'
Time frame: 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).
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.
Objective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Total Sleep Time'
Time frame: 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).
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.
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'
Time frame: 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).
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.
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'
Time frame: 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).
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.
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'
Time frame: 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).
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.
23 secondary outcomes
Mood/Affect
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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.
Dexterity
Time frame: 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.
Verbal Memory
Time frame: 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.
Cognitive Inhibition
Time frame: 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.
Individual Differences - Mini International Personality Item Pool (Mini-IPIP)
Time frame: Pre-intervention
Individual Differences - Dark Triad Personality Scale
Time frame: Pre-intervention
Individual Differences - Revised Circadian Type Inventory (CTI-R)
Time frame: Pre-intervention
Individual Differences - Horne-Östberg Morning-Eveningness Questionnaire (MEQ)
Time frame: Pre-intervention
Individual Differences - Genotypes
Time frame: Pre-intervention
Arousal prior to bedtime - one night between two day shifts versus one night between evening- followed by day shift
Time frame: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Quality'
Time frame: 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).
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'
Time frame: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Efficiency'
Time frame: 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).
Subjective Sleep,one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Sleep Onset Latency'
Time frame: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Bedtime'
Time frame: 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 - 'Wake after sleep onset'
Time frame: 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 - 'Sleep Efficiency'
Time frame: 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 - 'Bedtime'
Time frame: 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).
Subjective Sleep, one sleep opportunity between day- followed by day shift versus one sleep opportunity between evening- followed by day shift - 'Total Sleep Time'
Time frame: 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).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Aug 2023.
- Derived from this study: PubMed 39037118Holmelid 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.
- Individual participant dataSharing planned: No. After the project has ended the data will be anonymized and no direct recognizable information will be stored.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Short rest (8 hour) between two consecutive shifts. and 16 hour rest opportunity between to consecutive shifts. in people with Shift Work Schedule and Sleep Deprivation, run by University of Bergen at 1 site in Norway.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Aug 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sustained Attention (time frame: 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.). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05162105, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Aug 2023.