Light Treatment to Shift-working Nurses

The Effects of Bright Light on Adaptation to Night Work Among Nurses

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.

Study Overview

• Status: Completed
• Conditions: Shift-Work Sleep Disorder
• Intervention / Treatment: Behavioral: Bright light; Behavioral: Red light

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.

• Study Type: Interventional
• Enrollment (Actual): 35
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Norway
  • Hordaland
    • Bergen, Hordaland, Norway, 5018
      • University of Bergen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bright light; 10 000 lux	Behavioral: Bright 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).
Placebo Comparator: Red light; 400 lux	Behavioral: Red 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).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleepiness during the night shifts	Self-reported using the Karolinska Sleepiness Scale (KSS)	3 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Psychomotor vigilance during night shifts	Objective data from a 5 min computer based psychomotor vigilance test (PC-PVT) taken once during each night shift	3 days
Sleep after the night shifts	Self-reported using a sleep diary; objective data from actigraphs	3 days
Sleepiness during the days after the night shift period	Self-reported using the Karolinska Sleepiness Scale (KSS)	3 days
Sleep during the days after the night shift period	Self-reported using a sleep diary; objective data from actigraphs	3 days
Functioning on each shift, and shift period in total, compared to under normal conditions	Self-reported perception of effect of intervention	6 days

Collaborators and Investigators

• Sponsor: University of Bergen
• Investigators: Principal Investigator: Bjørn Bjorvatn, MD, PhD, University of Bergen

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2016
• Primary Completion (Actual): June 1, 2019
• Study Completion (Actual): June 1, 2019

Study Registration Dates

• First Submitted: November 25, 2016
• First Submitted That Met QC Criteria: November 25, 2016
• First Posted (Estimate): November 30, 2016

Study Record Updates

• Last Update Posted (Actual): October 2, 2019
• Last Update Submitted That Met QC Criteria: October 1, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Keywords: Sleep; Sleepiness; Bright light; Psychomotor vigilance
• Additional Relevant MeSH Terms: Mental Disorders; Nervous System Diseases; Dyssomnias; Neurologic Manifestations; Occupational Diseases; Chronobiology Disorders; Sleep Wake Disorders; Sleep Disorders, Circadian Rhythm
• Other Study ID Numbers: UiB112016

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No