NCT06440434

Effects of Morningness on Night Split Shift Performance

• Status: Active Not Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: University of Bergen · Academic / Other
• Sex: All
• Age: 18 Years – 40 Years
• Healthy volunteers: Accepted

Summary

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

Detailed 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).

Conditions

• Shift-work Disorder

Interventions

Type	Name	Description
BEHAVIORAL	Time of night shift	Early vs. late night split night shift

Timeline

• Start date: 2024-04-19
• Primary completion: 2024-06-20
• Completion: 2024-12-31
• First posted: 2024-06-03
• Last updated: 2024-06-13

Locations

1 site across 1 country: Norway