Circadian Rhythm DisordersNCT03331822
The Effects of Bright Light Exposure on ICU Nurses
A study testing Bright Light in people with Circadian Rhythm Disorders and Sleep, run by University of Pittsburgh at 1 site in United States.
Trial summary
In the majority of intensive care units, nurses work 12 hour shifts that consist of days and nights. Shift work outside of 6am-6pm has been reported to cause fatigue, induce sleep disorders, and cause metabolic disturbances. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Circadian Rhythm Disorders, Sleep
- What is being tested?
- Bright Light
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 31 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Oct 2017to 31 Dec 2017
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- All ICU nurses working at the University of Pittsburgh Trauma ICU.
Who cannot join
- Not working nights
Trial locations and contacts
1 site in 1 country.
United States1 site
Matthew R. Rosengart
Pittsburgh, Pennsylvania, 15217
About this study
In the majority of intensive care units, nurses work 12 hour shifts that consist of days and nights. Shift work outside of 6am-6pm has been reported to cause fatigue, induce sleep disorders, and cause metabolic disturbances. This shift to a nocturnal 'day' rather than diurnal, can result in reduced work performance, processing errors, accidents at work, absenteeism, and reduced quality of life. More chronically, those working at night have been shown to experience higher risks of heart disease, cancer and shorter median durations of life span. Much of this elevated risk is thought to be due to altered exposure to light, the dominant environmental cue regulating our circadian rhythms.
As diurnal organisms much of our biology is regulated by the solar day. Acutely, bright light exposure (i.e., sun) regulates the phase of the biological clock principally through the suppression of melatonin, which biologically mediates increased alertness and in essence, 'our daytime alertness'. During the night melatonin gradually increases and induces tiredness and ultimately sleep. This, in part, is biology behind the use of melatonin in those with sleep disturbances or to mitigate jet lag, with cross-continental or transoceanic flights.
In this study, the investigators will randomize nurses in the hospital to receive either high intensity white light (3,000 lux) or standard ambient white fluorescent (~400 lx) light for 10 hours during their night shift. This high illuminance light, rich in blue spectrum, is what diurnal creatures, like humans, are exposed to during the day. The lights may subsequently be equipped with blue filters (442 nm) to heighten the exposure to the rich blue spectrum light. Exposure will commence at the beginning of the night shift (~7pm) and continue for 10 hours. The rationale for terminating exposure prior to shift end is to foster an onset of sleep biology. At the end of each shift, the nurses will complete the Stanford Sleepiness Scale and the Psychomotor Vigilance Task (PVT). Saliva samples will be collected for melatonin level analysis and the nurses will complete sleep diaries at home. The investigators hypothesize that exposure to high intensity lighting during night shifts will reduce fatigue and enhance alertness and computational capacity that correlates with reduced melatonin.
Read the detailed description
This is randomized crossover trial, in which each nursing subject will serve as his or her own control: i.e., matched. The subjects will be nurses from the 6FG Trauma Intensive Care Unit at UPMC Presbyterian hospital. The PI or co-investigator will approach each nurse prior to the initiation of this study to obtain informed consent. Each nurse subject works approximately 7-8 nights out of 18 shifts in each month. The duration of this study is 1 month.
Each subject will be exposed to either the intervention or control arm solely based upon nursing assignment. Currently, nurses are assigned to care for patient on either the F or G side of the 6FG ICU, and there will be no changes made to shift assignments. For the purposes of this study, the F wing of the ICU will be ambient, standard white fluorescent environmental light and serve as control. The G wing of the ICU will be equipped with high illuminance white lights positioned throughout the hallway to generate a uniform exposure of approximately 3,000 lux. The current evidence suggests that >2000 lux is needed to achieve biological effects. The lights used are identical to those commercially available for the treatment of seasonal affective disorder. There have been over 70 clinical trials and several meta-analyses that have demonstrated the efficacy of light therapy for SAD. Adverse events were not significantly different between the light therapy and control groups. Thus, nurses will be assigned to either intervention or control based upon their standard nursing assignments.
At the end of each shift, subjects will complete the Stanford Sleepiness Scale on paper. This is the gold standard for subjective sleepiness levels. It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials. In addition, they will next complete the Psychomotor Vigilance Task (PVT) on their computer in the ICU. This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded. Subjects will be assessed a total of n=6 times during the period of study.
The quality of sleep the day following exposure to either intervention or control will be assessed through the use of a sleep diary. The Consensus Sleep Diary was developed in 2012 by a collaboration of insomnia experts. The subject will record what time they got into bed, time they went to sleep, how long to fall asleep, how many times they woke up, time they finally woke up, time they got out of bed, rate the quality of sleep, and how rested or refreshed they felt. Subjects will maintain 1 diary that will catalogue sleep during a total of n=6 night shifts.
The principle biologic mediator of sleep and wakefulness is melatonin. Saliva samples will be collected at the start of the shift (around 7pm) and at the end of the shift (around 7am). Samples will be stored at -80 degrees for future analysis. Nurses will be sampled a total of n=2 times. These samples will be stored for a maximum of 1 month. At the conclusion of the period of study and collection of all samples, which is estimated to be 1 month, all samples will be analyzed. No sample with be stored after analysis.
The subjects will complete the Stanford Sleepiness Scale on paper at the end of each shift. This is the gold standard for subjective sleepiness levels. It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials. In addition, they will next complete the Psychomotor Vigilance Task (PVT) on their computer in the ICU. This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded.
The quality of sleep the day following exposure to either intervention or control will be assessed through the use of a sleep diary. The Consensus Sleep Diary was developed in 2012 by a collaboration of insomnia experts. The subject will record what time they got into bed, time they went to sleep, how long to fall asleep, how many times they woke up, time they finally woke up, time they got out of bed, rate the quality of sleep, and how rested or refreshed they felt.
The principle biologic mediator of sleep and wakefulness is melatonin. Saliva samples will be collected at the start of the shift (around 7pm), at 3am (normal melatonin peak time), and at the end of the shift (around 6am). Samples will be stored at -80 degrees for future analysis.
- Conditions
- Circadian Rhythm Disorders, Sleep
- Being tested
- Bright Light
- Keywords
- circadian, light therapy, ICU nurse
- Medical subject headings
- Chronobiology Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Bright LightOther
high illuminance white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux. To achieve this illuminance, a Day*Light Classic Light will be positioned at each nursing station in the ICU hallway.
| Study group | Role | What they receive |
|---|---|---|
| Light | Experimental | High illuminance ,white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux. Receives: Other: Bright Light |
| No Light | No intervention | Ambient, standard white fluorescent environmental light will serve as control. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Psychomotor Vigilance Task
This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded.
Measured: Immediately at the end of the night shift worked.
Stanford Sleepiness Scale
It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials.
Measured: Immediately at the end of the night shift worked.
Secondary outcomes (2)
Consensus Sleep Diary
The Consensus Sleep Diary was developed in 2012 by a collaboration of insomnia experts. The subject will record what time they got into bed, time they went to sleep, how long to fall asleep, how many times they woke up, time they finally woke up, time they got out of bed, rate the quality of sleep, and how rested or refreshed they felt.
Measured: Throughout the course of the study for the night immediately following the night shift worked.
Salivary melatonin concentration
A saliva sample will be obtained immediately following the night shift worked. It will be assayed for melatonin concentration
Measured: Immediately at teh end of the night shift worked.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2017
- Study start15 Oct 2017
- Primary completion1 Dec 2017
- Study completion31 Dec 2017
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Circadian Rhythm DisordersStudies of the same condition, open and under way.
- More trials run by University of PittsburghThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This is randomized crossover trial, in which each nursing subject will serve as his or her own control: i.e., matched. The subjects will be nurses from the 6FG Trauma Intensive Care Unit at UPMC Presbyterian hospital.
- Masking
- None (open label)
- Enrolment
- 31 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Pittsburgh
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Matthew Rosengart, University of Pittsburgh
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03331822
- Sponsor's protocol ID
- PRO17010109
- Status last verified
- Dec 2018
- First submitted
- 1 Nov 2017
- Last updated
- 14 Dec 2018
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Griepentrog JE, Labiner HE, Gunn SR, Rosengart MR. Bright environmental light improves the sleepiness of nightshift ICU nurses. Crit Care. 2018 Nov 13;22(1):295. doi: 10.1186/s13054-018-2233-4.
PubMed 30424793
Study at a glance
From the registry record, last updated by the sponsor on 14 Dec 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effects of Bright Light Exposure on ICU Nurses
- ClinicalTrials.gov ID
- NCT03331822
- Acronym / sponsor ID
- PRO17010109
- Conditions
- Circadian Rhythm Disorders, Sleep
- Keywords
- circadian, light therapy, ICU nurse
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 31 participants (actual)
- Lead sponsor
- University of PittsburghUniversity, hospital or other
- Study start
- 15 Oct 2017 (actual)
- Primary completion
- 1 Dec 2017 (actual)
- Study completion
- 31 Dec 2017 (actual)
- First posted
- 6 Nov 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In the majority of intensive care units, nurses work 12 hour shifts that consist of days and nights. Shift work outside of 6am-6pm has been reported to cause fatigue, induce sleep disorders, and cause metabolic disturbances. This shift to a nocturnal 'day' rather than diurnal, can result in reduced work performance, processing errors, accidents at work, absenteeism, and reduced quality of life. More chronically, those working at night have been shown to experience higher risks of heart disease, cancer and shorter median durations of life span. Much of this elevated risk is thought to be due to altered exposure to light, the dominant environmental cue regulating our circadian rhythms.
As diurnal organisms much of our biology is regulated by the solar day. Acutely, bright light exposure (i.e., sun) regulates the phase of the biological clock principally through the suppression of melatonin, which biologically mediates increased alertness and in essence, 'our daytime alertness'. During the night melatonin gradually increases and induces tiredness and ultimately sleep. This, in part, is biology behind the use of melatonin in those with sleep disturbances or to mitigate jet lag, with cross-continental or transoceanic flights.
In this study, the investigators will randomize nurses in the hospital to receive either high intensity white light (3,000 lux) or standard ambient white fluorescent (~400 lx) light for 10 hours during their night shift. This high illuminance light, rich in blue spectrum, is what diurnal creatures, like humans, are exposed to during the day. The lights may subsequently be equipped with blue filters (442 nm) to heighten the exposure to the rich blue spectrum light. Exposure will commence at the beginning of the night shift (~7pm) and continue for 10 hours. The rationale for terminating exposure prior to shift end is to foster an onset of sleep biology. At the end of each shift, the nurses will complete the Stanford Sleepiness Scale and the Psychomotor Vigilance Task (PVT). Saliva samples will be collected for melatonin level analysis and the nurses will complete sleep diaries at home. The investigators hypothesize that exposure to high intensity lighting during night shifts will reduce fatigue and enhance alertness and computational capacity that correlates with reduced melatonin.
Detailed description
This is randomized crossover trial, in which each nursing subject will serve as his or her own control: i.e., matched. The subjects will be nurses from the 6FG Trauma Intensive Care Unit at UPMC Presbyterian hospital. The PI or co-investigator will approach each nurse prior to the initiation of this study to obtain informed consent. Each nurse subject works approximately 7-8 nights out of 18 shifts in each month. The duration of this study is 1 month.
Each subject will be exposed to either the intervention or control arm solely based upon nursing assignment. Currently, nurses are assigned to care for patient on either the F or G side of the 6FG ICU, and there will be no changes made to shift assignments. For the purposes of this study, the F wing of the ICU will be ambient, standard white fluorescent environmental light and serve as control. The G wing of the ICU will be equipped with high illuminance white lights positioned throughout the hallway to generate a uniform exposure of approximately 3,000 lux. The current evidence suggests that >2000 lux is needed to achieve biological effects. The lights used are identical to those commercially available for the treatment of seasonal affective disorder. There have been over 70 clinical trials and several meta-analyses that have demonstrated the efficacy of light therapy for SAD. Adverse events were not significantly different between the light therapy and control groups. Thus, nurses will be assigned to either intervention or control based upon their standard nursing assignments.
At the end of each shift, subjects will complete the Stanford Sleepiness Scale on paper. This is the gold standard for subjective sleepiness levels. It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials. In addition, they will next complete the Psychomotor Vigilance Task (PVT) on their computer in the ICU. This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded. Subjects will be assessed a total of n=6 times during the period of study.
The quality of sleep the day following exposure to either intervention or control will be assessed through the use of a sleep diary. The Consensus Sleep Diary was developed in 2012 by a collaboration of insomnia experts. The subject will record what time they got into bed, time they went to sleep, how long to fall asleep, how many times they woke up, time they finally woke up, time they got out of bed, rate the quality of sleep, and how rested or refreshed they felt. Subjects will maintain 1 diary that will catalogue sleep during a total of n=6 night shifts.
The principle biologic mediator of sleep and wakefulness is melatonin. Saliva samples will be collected at the start of the shift (around 7pm) and at the end of the shift (around 7am). Samples will be stored at -80 degrees for future analysis. Nurses will be sampled a total of n=2 times. These samples will be stored for a maximum of 1 month. At the conclusion of the period of study and collection of all samples, which is estimated to be 1 month, all samples will be analyzed. No sample with be stored after analysis.
The subjects will complete the Stanford Sleepiness Scale on paper at the end of each shift. This is the gold standard for subjective sleepiness levels. It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials. In addition, they will next complete the Psychomotor Vigilance Task (PVT) on their computer in the ICU. This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded.
The quality of sleep the day following exposure to either intervention or control will be assessed through the use of a sleep diary. The Consensus Sleep Diary was developed in 2012 by a collaboration of insomnia experts. The subject will record what time they got into bed, time they went to sleep, how long to fall asleep, how many times they woke up, time they finally woke up, time they got out of bed, rate the quality of sleep, and how rested or refreshed they felt.
The principle biologic mediator of sleep and wakefulness is melatonin. Saliva samples will be collected at the start of the shift (around 7pm), at 3am (normal melatonin peak time), and at the end of the shift (around 6am). Samples will be stored at -80 degrees for future analysis.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This is randomized crossover trial, in which each nursing subject will serve as his or her own control: i.e., matched. The subjects will be nurses from the 6FG Trauma Intensive Care Unit at UPMC Presbyterian hospital.
| Arm | Type | Receives |
|---|---|---|
| Light | Experimental | Other: Bright LightHigh illuminance ,white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux. |
| No Light | No intervention | –Ambient, standard white fluorescent environmental light will serve as control. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (1 listed)
- All ICU nurses working at the University of Pittsburgh Trauma ICU.
Key exclusion criteria (1 listed)
- Not working nights
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Bright Lighthigh illuminance white lights positioned at each nursing station throughout the hallway to generate a uniform exposure of approximately 1,000-3,000 lux. To achieve this illuminance, a Day*Light Classic Light will be positioned at each nursing station in the ICU hallway. | Other | Light |
Primary outcome
Psychomotor Vigilance Task
Time frame: Immediately at the end of the night shift worked.
This test is the standard objective measure of alertness and wakefulness. It has been employed as a marker of attention deficit in hundreds of studies to date. It is a 10 minute test in which the subjects look at a small rectangular screen and press the mouse every time a bright circle appears. The number of lapses (responses greater than 500 ms) is recorded.
Stanford Sleepiness Scale
Time frame: Immediately at the end of the night shift worked.
It was developed by Hoddes et al (1973) and is a simple 7-point rating scale. The scale is well validated and has been used in over 100 clinical trials.
2 secondary outcomes
Consensus Sleep Diary
Time frame: Throughout the course of the study for the night immediately following the night shift worked.
Salivary melatonin concentration
Time frame: Immediately at teh end of the night shift worked.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Dec 2018.
- Derived from this study: PubMed 30424793Griepentrog JE, Labiner HE, Gunn SR, Rosengart MR. Bright environmental light improves the sleepiness of nightshift ICU nurses. Crit Care. 2018 Nov 13;22(1):295. doi: 10.1186/s13054-018-2233-4.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Bright Light in people with Circadian Rhythm Disorders and Sleep, run by University of Pittsburgh at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Dec 2018. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Psychomotor Vigilance Task (time frame: Immediately at the end of the night shift worked.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03331822, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Dec 2018.