Effects of Morningness on Night Split Shift Performance

University of Bergen

Status: Active, not recruiting

Conditions: Shift-work Disorder

Treatments: Behavioral: Time of night shift

Study type: Interventional

Funder types: Other

Identifiers

NCT06440434

M3447

Details and patient eligibility

About

The goal is to investigate if the morningness-eveningness dimension mediates sleep and function on spilt night shifts (midnight-4am and 4am-8am).

Does those with high score of morningness function relatively better on the last compared to the first split shift?

Participants will:

Record their sleep from 2 days prior to 2 days following the split shift During the shifts complete questionnaires assessing mood, sleepiness and perceived performance as well as complete cognitive tests: Psychomotor vigilance test, digit symbol substitution test, working memory scanning test, reversal learning test, and visual search test

Full description

A sample of 28 students will be recruited and exposed to two conditions in a randomized, controlled, crossover study. They will be assessed with subjective (sleep diary) and objective sleep measures (sleep radar) for 2 days before the night shift, during the night shift and 2 days following the night shift. The simulated night shifts will last from midnight to 8am and will be divided into two halves (midnight-4am and 4am-8am), denoted as split-shift, and for each participant separated by at least 1 week. Based on the Horne-Östberg Morningness-Eveningness Questionnaire (median spilt) two groups are created, from which participants will be randomized to the two orders of the spilt-shift.

Each hour on each shift the participants will complete: Positive and Negative Affect Schedule (PANAS), Karolinska Sleepiness Scale, perceived performance and the following cognitive tests: Psychomotor vigilance test, Digit symbol substitution test, Working memory scanning test, Reversal learning test, and Visual search test.

Data will be analyzed with linear mixed models with three fixed factors: Group (low vs. high morningness), shift (midnight-4am vs. 4am-8am), and hour and one random factor (participant).

Enrollment: 30 estimated patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 18-40 years old
• no incorrectable vision problems

Exclusion criteria

* regular use of sleep medication

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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30 participants in 2 patient groups

Early night shift (midnight-4am)

Active Comparator group

Treatment:

Behavioral: Time of night shift

Late night shift (4am - 8am)

Active Comparator group

Treatment:

Behavioral: Time of night shift