Trial registered on ANZCTR


Trial ID
ACTRN12610000097044
Ethics application status
Approved
Date submitted
1/12/2009
Date registered
1/02/2010
Date last updated
15/04/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
Randomised controlled trial of a light intervention to enhance alertness and performance in healthy night shift workers.
Scientific title
Randomised controlled trial of a light intervention to enhance alertness and performance in healthy night shift workers.
Secondary ID [1] 1172 0
None
Universal Trial Number (UTN)
Trial acronym
LAPS (Light and Performance in Shiftworkers)
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Alertness, mood and cognitive performance in healthy human volunteers. 252236 0
Condition category
Condition code
Mental Health 252422 252422 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will be exposed to High Colour Temperature Light (HCT; 17,000K, 200 lux) administered using Philips EnergyLight HF3309 lamps or a panel of Light Emitting Diodes.

Participants will visit a light controlled, sound attenuated, temperature controlled laboratory from 6:00pm to 8:30am. Exposure to the light will occur in one intervention from 11:00pm to 7:00am. During the light exposure participants will be required to stay awake and complete computer or paper based assessments of their mood and performance, while seated. The rest of the time participants will be allowed to do quiet tasks such as reading, puzzles or card games.
Intervention code [1] 241568 0
Behaviour
Intervention code [2] 241569 0
Treatment: Devices
Comparator / control treatment
Participants randomized into the control condition will be exposed to Low Colour Temperature Light (LCT; 4,000K, 200 lux).

This light condition is the equivalent of standard lighting conditions and is not expected to have any treatment value.

Participants will visit a light controlled, sound attenuated, temperature controlled laboratory from 6:00pm to 8:30am. Exposure to the light will occur in one intervention from 11:00pm to 7:00am. During the light exposure participants will be required to stay awake and complete computer or paper based assessments of their mood and performance, while seated. The rest of the time participants will be allowed to do quiet tasks such as reading, puzzles or card games.
Control group
Active

Outcomes
Primary outcome [1] 253297 0
Psychomotor Vigilance Task mean reaction time (msec) and number of lapses/long responses.
Timepoint [1] 253297 0
This outcome is assessed in a test of reaction times to a repeated auditory stimulus. The test will be repeated within a larger test battery which will include the following tests (1) Karolinska Sleepiness Scale, (2) Mood Scales, (3) Psychomotor Vigilance Task, (4) Performance Effort and Evaluations Rating and (5) Karolinska Drowsiness Test.

This test battery will occur every hour before light exposure, at 7pm, 8pm, 9pm and 10pm. During light exposure it is administered every 2 hours, at 11pm, 1am, 3am and 5am. It will also be administered every hour after the light exposure, at 7am and 8am.
Primary outcome [2] 253366 0
The Karolinska Drowsiness Test, sleepiness as assessed by waveforms on the Electroencephalogram (EEG) and Electrooculogram (EOG).
Timepoint [2] 253366 0
This outcome will be assessed within a larger test battery which will include the following tests (1) Karolinska Sleepiness Scale, (2) Mood Scales, (3) Psychomotor Vigilance Task, (4) Performance Effort and Evaluations Rating and (5) Karolinska Drowsiness Test.

This test battery will occur every hour before light exposure, at 7pm, 8pm, 9pm and 10pm. During light exposure it is administered every 2 hours, at 11pm, 1am, 3am and 5am. It will also be administered every hour after the light exposure, at 7am and 8am.
Primary outcome [3] 253367 0
Subjective sleepiness rating on the Karolinska Sleepiness Scale of 1-9.
Timepoint [3] 253367 0
This outcome will be assessed within a larger test battery which will include the following tests (1) Karolinska Sleepiness Scale, (2) Mood Scales, (3) Psychomotor Vigilance Task, (4) Performance Effort and Evaluations Rating and (5) Karolinska Drowsiness Test.

This test battery will occur every hour before light exposure, at 7pm, 8pm, 9pm and 10pm. During light exposure it is administered every 2 hours, at 11pm, 1am, 3am and 5am. It will also be administered every hour after the light exposure, at 7am and 8am.
Secondary outcome [1] 262474 0
Subjective ratings of mood on scale of 1-9 and the Profile of Mood States (Bi-POMS).
Timepoint [1] 262474 0
The Subjective ratings of mood on the 1-9 scale will be assessed within the repeated test battery. This test battery will occur every hour before light exposure, at 7pm, 8pm, 9pm and 10pm. During light exposure it is administered every 2 hours, at 11pm, 1am, 3am and 5am. It will also be administered every hour after the light exposure, at 7am and 8am.


The Profile of Mood States (Bi-POMS) will be assessed approximately 1 hour 40 minutes (7:40pm) after arriving at the Sleep Laboratory, before the light exposure. It will also be assessed during the light exposure, after approximately 3 hours 30 minutes of light exposure.
Secondary outcome [2] 262475 0
Performance on the Dual Task, including reaction time and false responses.

This task runs on a computer and involves responding as quickly as possible to a visual stimulus appearing on the screen.
Timepoint [2] 262475 0
This will be assessed approximately 3 hours 50 minutes after arriving at the Sleep Laboratory, before the light exposure. This will also be assessed during light exposure, after approximately 5 hours 30 minutes of light exposure.
Secondary outcome [3] 262476 0
Performance on the AusEd driving simulator, including speed deviations, lane drift and collisions during simulated driving.

The AusEd Driving simulator is a personal computer based task which simulates a monotonous night time drive on a rural road.
Timepoint [3] 262476 0
This will be assessed once during the last hour of light exposure.
Secondary outcome [4] 262542 0
Subjective rating of reaction time performance on the Performance Effort and Evaluations Rating Scale (PEERS).
Timepoint [4] 262542 0
This outcome will be assessed within the larger test battery which will include the following tests (1) Karolinska Sleepiness Scale, (2) Mood Scales, (3) Psychomotor Vigilance Task, (4) Performance Effort and Evaluations Rating and (5) Karolinska Drowsiness Test.

This test battery will occur every hour before light exposure, at 7pm, 8pm, 9pm and 10pm. During light exposure it is administered every 2 hours, at 11pm, 1am, 3am and 5am. It will also be administered every hour after the light exposure, at 7am and 8am.

Eligibility
Key inclusion criteria
(1) Male and female adults aged 18 to 65 years inclusive.
(2) Healthy.
(3) Engaged in 5 or more night shifts per month.
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
(1) Individuals who report high caffeine, nicotine and/or alcohol intake. (2) Individuals who screen positive for drugs of abuse following comprehensive urine toxicological analysis. (3) Women who are pregnant, lactating or planning to become pregnant during the study period. (4) A history of alcohol/drug dependence. (5) Current, recent (<3 months) or chronic history of use of drugs or medication that affect the central nervous system (except non-steroid topical creams, oral contraceptives and occasional use of mild pain killers). (6) History of psychiatric illness on the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM IV Axis 1). (7) History of cardiovascular disease. (8) Abnormal sleep patterns/sleep disorders. (9) Auditory defects (accepted if corrected with hearing aids). (10) Any form of photophobia including drug-induced, epilepsy, seizures, vertigo or migraine. (12) Individuals with diseases of the visual system. (13) Females who are not taking a medically approved form of birth control.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The person who determines if a subject is eligible will be unaware of which group the subject will be allocated.

Subjects will not be allocated to a group until the day they visit the Sleep Laboratory. The allocation schedule will be held by one individual at each of the three sites. It will be concealed using a password protected computer file and will only be referred to immediately prior to the light exposure.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Two randomization tables will be used. One to randomize one participant at a time, another for randomizing two participant's at a time. The tables will be formulated by a statistician off-site.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Current
Final
Recruitment in Australia
Recruitment state(s)
NSW,SA,VIC

Funding & Sponsors
Funding source category [1] 256096 0
Government body
Name [1] 256096 0
National Health and Medical Research Council
Address [1] 256096 0
Level 5, 20 Allara Street, Canberra, ACT 2601
Country [1] 256096 0
Australia
Primary sponsor type
University
Name
Monash University
Address
Wellington Road, Clayton, VIC, 3800
Country
Australia
Secondary sponsor category [1] 251439 0
University
Name [1] 251439 0
The University of Sydney
Address [1] 251439 0
88-100 Mallett Street, Camperdown, NSW, 2050
Country [1] 251439 0
Australia
Secondary sponsor category [2] 251455 0
University
Name [2] 251455 0
Unviersity of South Australia
Address [2] 251455 0
North Terrace, Adelaide, SA, 5000
Country [2] 251455 0
Australia
Other collaborator category [1] 986 0
University
Name [1] 986 0
The University of Adelaide
Address [1] 986 0
The University of Adelaide, SA, 5005
Country [1] 986 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 258185 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 258185 0
Building 3e, Research Office, Monash University, VIC, 3800
Ethics committee country [1] 258185 0
Australia
Date submitted for ethics approval [1] 258185 0
Approval date [1] 258185 0
09/01/2009
Ethics approval number [1] 258185 0
CF08/3287 - 2008001604
Ethics committee name [2] 258195 0
Human Research Ethics Committee of the Universities of New South Wales and Sydney
Ethics committee address [2] 258195 0
Jane Foss Russell Building G02, The University of Sydney, NSW, 2006
Ethics committee country [2] 258195 0
Australia
Date submitted for ethics approval [2] 258195 0
Approval date [2] 258195 0
01/06/2009
Ethics approval number [2] 258195 0
05-2009/11697
Ethics committee name [3] 294838 0
University of South Australia Human Research Ethics Committee
Ethics committee address [3] 294838 0
GPO Box 2471
Adelaide
South Australia 5001
Australia
Ethics committee country [3] 294838 0
Australia
Date submitted for ethics approval [3] 294838 0
09/04/2009
Approval date [3] 294838 0
08/05/2009
Ethics approval number [3] 294838 0
P114/09

Summary
Brief summary
This study has been designed to investigate the efficacy of short wavelength enriched light exposure as a therapeutic intervention for the adverse neurobehavioural consequences of sleep loss and circadian rhythm disruption in night shift workers, and to examine retrospectively whether individual differences in responsiveness to light can be predicted by circadian phase estimates and genetic differences.

The study will be carried out at three different sites, these include (1) Monash University, (2) The University of Sydney and (3) University of South Australia.
Trial website
N/A
Trial related presentations / publications
Ftouni S, Sletten TL, Nicholas CL, Kennaway DJ, Lockley SW, Rajaratnam SMW. Ocular measures of sleepiness are increased in night shift workers undergoing a simulated night shift near the peak time of the 6-Sulfatoxymelatonin rhythm. 2015, Journal of Clinical Sleep Medicine, 11(10), 1131-1141.

Magee M, Sletten TL, Ferguson SA, Grunstein RR, Anderson C, Kennaway DJ, Lockley SW, Rajaratnam SMW. Associations between number of consecutive night shifts and impairment of neurobehavioural performance during subsequent simulated night shift. 2016, Scandinavian Journal of Work, Environment & Health, doi:10.5271/sjweh.3560.
Public notes

Contacts
Principal investigator
Name 30524 0
Prof Shantha Rajaratnam
Address 30524 0
Monash University, School of Psychological Sciences, Building 17, Clayton, Victoria 3800 Australia
Country 30524 0
Australia
Phone 30524 0
+61 3 9905 3934
Fax 30524 0
Email 30524 0
shantha.rajaratnam@monash.edu
Contact person for public queries
Name 13771 0
Prof Shantha Rajaratnam
Address 13771 0
Monash University, School of Psychological Sciences, Building 17, Clayton, Victoria 3800 Australia
Country 13771 0
Australia
Phone 13771 0
+61 3 9905 3934
Fax 13771 0
+61 3 9905 3948
Email 13771 0
shantha.rajaratnam@med.monash.edu.au
Contact person for scientific queries
Name 4699 0
Prof Shantha Rajaratnam
Address 4699 0
Monash University, School of Psychological Sciences, Building 17, Clayton, Victoria 3800 Australia
Country 4699 0
Australia
Phone 4699 0
+61 3 9905 3934
Fax 4699 0
+61 3 9905 3948
Email 4699 0
shantha.rajaratnam@med.monash.edu.au