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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Evaluating a portable device to advance the internal body clock to treat insomnia
Scientific title
Evaluation of a portable light device for phase advancing the circadian rhythms of those suffering from sleep-onset insomnia
Secondary ID [1] 297856 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record
Lau, T., Lovato, N., & Lack, L. (2018). Evaluation of a portable light device for phase advancing the circadian rhythm in the home environment. Sleep and Biological Rhythms, 16(4), 405-411.

This study investigated the use of Re-Timer in the home with good sleepers, whilst this present follows up on this by investigating on the use of Re-Timers in the home environment in those with Sleep Onset Insomnia.

Health condition
Health condition(s) or problem(s) studied:
Chronic Insomnia Disorder 312790 0
Sleep Onset Insomnia 313505 0
Condition category
Condition code
Mental Health 311288 311288 0 0
Other mental health disorders
Neurological 311934 311934 0 0
Other neurological disorders

Study type
Description of intervention(s) / exposure
During the treatment week of the study, participants in the treatment condition will use the Re-Timer device to administer bright light therapy. Re-Timers are a portable, lightweight, glasses-like device (Re-Timer Pty. Ltd., Adelaide). In the treatment condition, it administers blue-green light (~500 nm) into the participants visual field, via four Light-Emitting Diodes (LEDs) mounted on the lower frame underneath the eyes. When measured at 20mm from the distance of the eye, the light administered is at an intensity of 506 Lux lm/m2and 230 µW/cm2 (high setting). Re-Timer is worn exactly like glasses and positioned so that the light is directly administered into the visual field.

Twenty-four participants will be randomly allocated to either the treatment or control condition. For the twelve participants in the treatment condition, Re-Timer will administer blue/green light. A Re-Timer device will be given to each participant to wear in their own homes for 60 minutes every morning during the treatment week (7 days of exposure). As the device must be worn, participants will administer the treatment themselves in their own homes.

To evaluate the efficacy of the Re-Timer device, dim light melatonin onset (DLMO) and skin temperature will be measured as a marker of circadian rhythms. Participants will collect their own saliva samples for DLMO and apply iButtons to measure skin temperature.

On day 2 of the treatment week, participants were not allowed to consume food after 17:30 hours as some foods interfere with salivary melatonin concentrations. Six hours before habitual bedtime, participants will sit in a dimly lit room (<10 Lux) for 1 hour and start collecting their own saliva samples at half-hourly intervals from 5-hours before participant’s habitual bed until 2- hours after habitual bedtime. Participants were instructed on how to store these samples to return them. During the saliva collection period, participants could watch television and read but will not be allowed to work on a computer or use a mobile device as the emitted light interferes with melatonin secretion. One hour before their habitual bedtime, participants also completed the Stanford Sleepiness Scale. Upon the final Saliva collection for the night, participants could sleep. Additionally, at the same time as the initial saliva collection, participants wore the iButtons until the following morning.
On the morning of day 3, participants will awake 20 minutes earlier than their habitual wake-up time and wear the Re-Timer for 60 minutes. During this time the participants completed their sleep diary and the light sensitivity questionnaire. The participant’s day was then unregulated until 1 hour before their habitual bedtime, in which time they completed the Stanford Sleepiness Scale and sat in a dimly lit room (<10 Lux). They were told to go to bed when they are ready.
For the next five days, participants repeated the same protocol as on day 3. But, instead of waking up 20 minutes earlier than their habitual wake-up time, they would wake up 20 minutes earlier and earlier than day before. This in combination with Re-Timer will slowly phase advance their circadian rhythm.
Upon the eighth night, the protocol DLMO measurement for day two was repeated for comparison.
Adherence to Re-Timer usage is ensured via the participant sleep diary and reminder text messages.
Intervention code [1] 314440 0
Treatment: Devices
Comparator / control treatment
The control condition in this study will be randomly allocated 12 out of 24 participants. The control condition will be identical to the treatment condition, but participants will use blue-light blocking glasses instead of Re-Timer. Re-Timer and the blue-light blocking glasses are both worn like glasses, but do not appear identical.
Control group

Primary outcome [1] 320032 0
Phase advance of the circadian rhythm as measured by Dim Light Melatonin Onset via saliva samples
Timepoint [1] 320032 0
Days 2 and 8 of treatment week
Primary outcome [2] 320106 0
Sleep onset latency as measured by sleep diaries and Actigraphy
Timepoint [2] 320106 0
Mean days 1-7 pre-treatment, mean days 1-7 post-treatment (primary endpoint), and mean days 1-7 follow-up (follow-up begins one week after treatment week ends)
Secondary outcome [1] 370308 0
Night-time sleepiness as measured the Stanford Sleepiness Scale
Timepoint [1] 370308 0
Days 2 and 8 of treatment week
Secondary outcome [2] 370546 0
Insomnia symptoms as measured by the Insomnia Severity Scale
Timepoint [2] 370546 0
Mean days 1-7 pre-treatment, mean days 1-7 post-treatment, and mean days 1-7 follow-up

Key inclusion criteria
Symptoms that meet the criteria for a diagnosis of insomnia, according to the ICSD-3. Specifically;
1. Sleep diary data which indicates difficulties initiating sleep (>30-minute latency to sleep) at least three times in the one-week screening assessment period.
2. Sleep and daytime functioning questionnaire scores which indicate insomnia:
o Insomnia Severity Index >10
Minimum age
18 Years
Maximum age
64 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
a) Taking any medication that would affect sleep/melatonin production
b) Had recent eye surgery or a chronic eye condition,
c) Difficulties with the English language that would prevent informed consent,
d) Receiving other forms of sleep treatment,
e) Diagnosis of sleep disorder other than insomnia,
f) Were habitual high consumers of caffeine (greater than or equal to 250 mg daily) and/or alcohol (greater than or equal to 14 standard drinks per week),
g) Indicated a history of substance abuse in the last 12 months,
h) Worked a night shift in the previous 2 months (night shift was defined as a work schedule including at least 6 h of work between 10:00 p.m. And 8:00 a.m.),
i) Undertook trans-meridian travel (two time zones) in the last 2 months,
j) Pregnant or lactating, or
k) Clinically diagnosed depression.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will be randomly allocated to either the treatment condition or the control condition using block randomisation from computer software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

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

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 302382 0
Name [1] 302382 0
Flinders University Consulting Account
Address [1] 302382 0
Sturt Rd
Bedford Park
Adelaide, South Australia 5042
Country [1] 302382 0
Primary sponsor type
Flinders University
Sturt Rd
Bedford Park
Adelaide, South Australia 5042
Secondary sponsor category [1] 302883 0
Name [1] 302883 0
Address [1] 302883 0
Country [1] 302883 0

Ethics approval
Ethics application status
Ethics committee name [1] 303055 0
Southern Adelaide Clinical Human Research Ethics Committee (SAC HREC)
Ethics committee address [1] 303055 0
Human Research Ethics, Room 2A
221 Flinders Medical Centre
Level 2, Flinders Medical Centre
Ethics committee country [1] 303055 0
Date submitted for ethics approval [1] 303055 0
Approval date [1] 303055 0
Ethics approval number [1] 303055 0

Brief summary
This study will examine how bright light administered in the morning will advance the internal body clock and reduce the symptoms of sleep onset insomnia. Sleep onset insomnia is chronic insomnia disorder that is primarily caused a difficulty initiating sleep. Re-Timer has previously been used to shift the internal body clock in good sleepers in the home environment. This study will build upon these findings by examining those with sleep onset insomnia in the home environment.
It will be predicted that the individual's internal body clock will be advanced, night time sleepiness will increase, time taken to fall asleep will decrease, and insomnia symptoms will decrease.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 92302 0
Dr Nicole Lovato
Address 92302 0
Adelaide Institute for Sleep Health. 5 Laffer Drive, Bedford Park, SA 5042
Country 92302 0
Phone 92302 0
+61 8 7221 8307
Fax 92302 0
Email 92302 0
Contact person for public queries
Name 92303 0
Dr Nicole Lovato
Address 92303 0
Adelaide Institute for Sleep Health. 5 Laffer Drive, Bedford Park, SA 5042
Country 92303 0
Phone 92303 0
+61 8 7221 8307
Fax 92303 0
Email 92303 0
Contact person for scientific queries
Name 92304 0
Dr Nicole Lovato
Address 92304 0
Adelaide Institute for Sleep Health. 5 Laffer Drive, Bedford Park, SA 5042
Country 92304 0
Phone 92304 0
+61 8 7221 8307
Fax 92304 0
Email 92304 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
There are ethical and logistical considerations that would prevent IPD sharing.
What supporting documents are/will be available?
No other documents available
Summary results
No Results