Shift-Work Sleep Disorder
Conditions
Keywords
Bright light, Sleepiness, Sleep, Psychomotor vigilance
Brief summary
This project examines 1) the effects of appropriately timed bright light on adaptation (in terms of sleep and sleepiness) to three consecutive night shifts; and 2) the effects of such bright light on re-adaptation (in terms of sleep and sleepiness) to a day-oriented schedule after the night shift period.
Detailed description
Shift workers frequently experience sleepiness during night shifts, which may have consequences for performance. Sleep duration is often shortened after a night shift. Properly timed bright light treatment is efficient in delaying the circadian rhythm and can enhance alertness, increase performance and prolong sleep after night shifts. There is a lack of studies on light treatment to rotating shift workers. This study is a randomized controlled crossover trial evaluating the effect of bright light treatment on sleep and sleepiness in rotating shift workers with three consecutive night shifts. The aim is to evaluate whether bright light treatment improves adaptation to three consecutive night shifts (reduces sleepiness during night shifts and improves sleep after night shifts), as well as whether such treatment affects re-adaptation to a day-oriented schedule after the night shift period.
Interventions
BEHAVIORALBright light
Bright light for 30 minutes during night shifts (between 2 AM and 3 AM the first night, between 3 AM and 4 AM the second night, between 4 AM and 5 AM the third night).
BEHAVIORALRed light
Red light for 30 minutes during night shifts (between 2 AM and 3 AM the first night, between 3 AM and 4 AM the second night, between 4 AM and 5 AM the third night).
Sponsors
University of Bergen
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* A rotating shift work schedule involving three days without night shifts, followed by three consecutive night shifts, followed by three days without night shifts * Problems with sleepiness during night shifts
Exclusion criteria
* Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sleepiness during the night shifts | 3 days | Self-reported using the Karolinska Sleepiness Scale (KSS) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Psychomotor vigilance during night shifts | 3 days | Objective data from a 5 min computer based psychomotor vigilance test (PC-PVT) taken once during each night shift |
| Sleep after the night shifts | 3 days | Self-reported using a sleep diary; objective data from actigraphs |
| Sleepiness during the days after the night shift period | 3 days | Self-reported using the Karolinska Sleepiness Scale (KSS) |
| Sleep during the days after the night shift period | 3 days | Self-reported using a sleep diary; objective data from actigraphs |
| Functioning on each shift, and shift period in total, compared to under normal conditions | 6 days | Self-reported perception of effect of intervention |
Countries
Norway
Outcome results
None listed