Quick Returns - Sleep, Cognitive Functions and Individual Differences

University of Bergen

Status: Completed

Conditions: Sleep Deprivation; Shift Work Schedule

Treatments: Other: Short rest (8 hour) between two consecutive shifts.; Other: 16 hour rest opportunity between to consecutive shifts.

Study type: Interventional

Funder types: Other

Identifiers

NCT05162105

303671

Details and patient eligibility

About

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.

Full 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.

Enrollment: 80 patients

Sex: All

Ages: 19 to 50 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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80 participants in 2 patient groups

Evening shift followed by day shift (Quick Return)

Experimental group

Description:

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.

Treatment:

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

Day shift followed by day shift

Active Comparator group

Description:

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.

Treatment:

Other: 16 hour rest opportunity between to consecutive shifts.