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Trial registered on ANZCTR


Registration number
ACTRN12617000001392
Ethics application status
Approved
Date submitted
30/11/2016
Date registered
3/01/2017
Date last updated
21/08/2020
Date data sharing statement initially provided
30/07/2019
Date results information initially provided
21/08/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
The effects of 3 days of simulated wind farm infrasound, sham infrasound and traffic noise on health: A laboratory-based randomised, 3 way cross over study
Scientific title
The effects of 3 days of simulated wind farm infrasound, sham infrasound and traffic noise on health in people who are noise sensitive: A laboratory-based randomised, 3 way cross over study
Secondary ID [1] 290659 0
Australian NH&MRC Project Grant APP1113615
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Wind Turbine Syndrome 301185 0
Sleep Disruption 301186 0
Condition category
Condition code
Neurological 300939 300939 0 0
Studies of the normal brain and nervous system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will be exposed during three 3-day continuous periods (i.e. 72 continuous hours in our single bedroom apartment-like sleep laboratory rooms), in random order to the 2 control conditions and the key exposure of:
1. wind farm simulated infrasound at 90dB Pk (test exposure) generated by specially manufactured speaker boxes

The washout period between exposures will be at least 11 days

Intervention code [1] 296538 0
Other interventions
Comparator / control treatment
1. no added sound (sham, negative control). Speaker boxes identical to the infrasound generating boxes used for the wind farm exposure will be placed in the participants’ rooms (negative control)
2. traffic noise at 40-50LAeq with breakthrough events at 70dB Pk (positive or active control)
Control group
Placebo

Outcomes
Primary outcome [1] 300360 0
Changes in minutes of wake after sleep onset (WASO) as determined by 3 overnight polysomnograms per arm using standard electroencephalography (EEG) based criteria. We will compare the effects of infrasound and traffic noise to sham infrasound. Minutes of WASO is calculated from the first epoch of any sleep detected on the polysomnogram until the last epoch of any sleep detected on the polysomnogram or the particpant's individually calculated actigraphically estimated wake-up time, whichever happens last.
Timepoint [1] 300360 0
All 3 nights of exposure to each of the 3 exposures will be combined
Secondary outcome [1] 329777 0
Sleep latency (Time to onset of 1st sleep at night as determined by a polysomnograph)
Timepoint [1] 329777 0
All 3 nights of exposure to each of the 3 exposures will be combined
Secondary outcome [2] 329778 0
Sleep Stage Shifts (The total number of sleep stage transitions over the whole night as determined by a polysomnograph)
Timepoint [2] 329778 0
All 3 nights of exposure to each of the 3 exposures will be combined
Secondary outcome [3] 329779 0
Proportions of the sleep opportunity period scored as stage Wake or as sleep stages N1, N2, N3 and REM as recorded on a polysomnograph
Timepoint [3] 329779 0
All 3 nights of exposure to each of the 3 exposures will be combined
Secondary outcome [4] 329780 0
Arousal frequency (the Arousal Index is a measure of the number or cortical arousals captured via the EEG on a polysomnograph per hour of scored sleep)
Timepoint [4] 329780 0
All 3 nights of exposure to each of the 3 exposures will be combined
Secondary outcome [5] 329781 0
Power spectral analysis for sleep microarchitecture analysis
Quantitative EEG analysis techniques will be applied to all sleep EEG signals from polysomnography recordings after identification and exclusion of artefacts. Sleep stage specific power spectra using a fast Fourier transform routine and scaling exponents from detrended fluctuation analysis will be quantified. Sleep spindle characteristics including density (no. of spindles/min of NREM), duration, and morphology (frequency, amplitude and symmetry), and dynamics of slow wave activity (SWA) across the night will also be computed. The topographical and regional distribution of sleep EEG oscillations (i.e. SWA, K-complexes and sleep spindles) will be examined to detect changes in cortical activity across key brain regions that may occur from the study interventions. EEG data will be collected using established data acquisition processes using hospital approved sleep recording systems in the sleep laboratory. Analysis of EEG data will be performed through internally developed and validated software as well as PhiTools PRANA software.
Timepoint [5] 329781 0
All 3 nights of exposure to each of the 3 exposures will be combined

Eligibility
Key inclusion criteria
1. Aged 18 or above
2. Noise sensitive individuals -defined as Weinstein’s Noise Sensitivity Scale (WNS) Score >58
3. Normal hearing on audiometry
4. Clinically normal 24-hr sleep-wake cycle as assessed by actigraphy for at least 7 nights, with >5.5hrs sleep/night on average and a normal rise time between 5am & 7am and a normal bedtime between 9pm & 1am
5. Fluent in English. Must be able to answer computerised questionnaires and undergo neurocognitive assessments in English
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Any previous clinically evident and uncontrolled severe sleep disorders, including severe insomnia as assessed by the Insomnia Severity Index (moderate = >18 will be excluded)
2. No serious chronic illnesses
3. No major psychiatric disorders
4. Use of any hypnotic medications or other medications that interfere with sleep within the last month
5. Recent time-zone travel (more than 2 time zones in the last 2 weeks or 1 time zone in the past week)
6. Shift workers
7. Pregnant, expecting or breastfeeding women
8. Unable to remain in a sleep lab for 4 consecutive days
9. Unable to refrain from tobacco, alcohol or caffeine during study visits.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Secure randomisation will be achieved through Research Tools(TM) by entering secure participant data in order to access a unique participant randomisation number. The unique participant number will be assigned in ascending chronological order. This number will be a two digit number prefixed by “R” (e.g. R01, R02 etc.) and will be used to identify the randomised study period order the participant undergoes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Participants will undertake the 3 study periods in a random order. An investigator who will never meet any participant and plays no role in selection or testing of participants will computer generate the randomisation list.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Crossover
Other design features
Expectations on the part of participants and investigators may influence the effect of the exposure (infrasound) and, more particularly, may influence the measurement of those effects, especially the subjective (self-reported) outcomes. To avoid the potential for this measurement bias, it is important that both participants and the investigators who are measuring outcomes are blinded to the intervention group. Fortunately, as infrasound is, by definition, inaudible, this is readily achieved by the use of a sham device that appears the same as the infrasound device, but which does not produce any sound. Only the unblinded acoustic engineer will have knowledge of the exposure and they will never meet a participant.
The study will also include a positive control arm. During this period, participants will be exposed to actual noise (traffic noise). The purpose of this arm is to demonstrate that both the participants and the tools used to measure outcomes are sensitive enough to be responsive to a sound-stimulus. It would be particularly important to demonstrate that this is the case if we fail to observe any effect of the test stimulus (infrasound) on the health outcomes that are being measured. As the positive control consists of actual sound, it will not be possible to blind participants or investigators to this exposure.
Phase
Not Applicable
Type of endpoint(s)
Safety
Statistical methods / analysis
Generalised linear mixed models will be utilised for statistical analysis. WASO will be the dependent variable in the primary analysis. All other outcomes will be tested separately as dependent variables. Exposure (infrasound vs sham) will be the main fixed effect and its coefficient will be the estimate of difference in the outcome attributable to infrasound (vs sham) exposure. Participants will be included as a random effect, a period effect (first, second or third exposure period) will be included as an additional fixed effect and a term representing the sequence (or order) will be included as an additional random effect (nested within participants). As multiple outcome measures will be made (at baseline and at various follow-up times) a “time” fixed effect will also be included and exposure-by-time interactions will be tested. Also, the exposure-by-anxiety/stress about Wind Turbine Syndrome interaction will be tested to establish whether this attribute modifies the propensity to experience Wind Turbine Syndrome symptoms with exposure.

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
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 14765 0
2037 - Glebe

Funding & Sponsors
Funding source category [1] 295088 0
Government body
Name [1] 295088 0
NHMRC
Address [1] 295088 0
GPO Box 1421 Canberra ACT 2601
Country [1] 295088 0
Australia
Primary sponsor type
Other
Name
Woolcock Institute for Medical Research
Address
431 Glebe Pt Rd
Glebe 2037
NSW
Country
Australia
Secondary sponsor category [1] 293908 0
None
Name [1] 293908 0
Address [1] 293908 0
Country [1] 293908 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 296442 0
Sydney Local Health District Ethics Review Committee (Royal Prince Alfred Hospital Zone)
Ethics committee address [1] 296442 0
c/o Research Development Office
Royal Prince Alfred Hospital
Missenden Road
Camperdown NSW 2050
Ethics committee country [1] 296442 0
Australia
Date submitted for ethics approval [1] 296442 0
04/11/2016
Approval date [1] 296442 0
02/12/2016
Ethics approval number [1] 296442 0
X16-0073 & HREC/16/RPAH/91

Summary
Brief summary
This short-term, randomised, 3 period, crossover study, which will be conducted in our purpose-built, sound-isolated laboratory at the Woolcock Institute. Because of rising community concerns about the health effects of infra sound generated by wind turbines we will measure the impact of exposure to infrasound on multiple dimensions of human health in individuals who report increased noise sensitivity.
Trial website
https://www.windfarmstudy.com
Trial related presentations / publications
Public notes
Attachments [1] 1337 1337 0 0
Attachments [2] 1742 1742 0 0

Contacts
Principal investigator
Name 70862 0
A/Prof Nathaniel Marshall
Address 70862 0
Woolcock Institute for Medical Research
431 Glebe Pt Rd
Glebe
NSW 2037
Country 70862 0
Australia
Phone 70862 0
+61 2 9114 0000
Fax 70862 0
Email 70862 0
nathaniel.marshall@sydney.edu.au
Contact person for public queries
Name 70863 0
A/Prof Nathaniel Marshall
Address 70863 0
Woolcock Institute for Medical Research
431 Glebe Pt Rd
Glebe
NSW 2037
Country 70863 0
Australia
Phone 70863 0
+61 2 9114 0000
Fax 70863 0
Email 70863 0
nathaniel.marshall@sydney.edu.au
Contact person for scientific queries
Name 70864 0
A/Prof Nathaniel Marshall
Address 70864 0
Woolcock Institute for Medical Research
431 Glebe Pt Rd
Glebe
NSW 2037
Country 70864 0
Australia
Phone 70864 0
+61 2 9114 0000
Fax 70864 0
Email 70864 0
nathaniel.marshall@sydney.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
All non-identifiable data
When will data be available (start and end dates)?
1/6/21 to 1/6/31
Available to whom?
Only researchers who provide a methodologically sound proposal
Available for what types of analyses?
Individual participant level meta-analyses of congruent studies
How or where can data be obtained?
By email application to nathaniel.marshall@sydney.edu.au with a properly constituted research plan and ethical approval (or plan to get such)
What supporting documents are/will be available?
Study protocol
Informed consent form
Ethical approval
Analytic code
How or where can supporting documents be obtained?
Type [1] 8904 0
Study protocol
Citation [1] 8904 0
Link [1] 8904 0
Email [1] 8904 0
nathaniel.marshall@sydney.edu.au
Other [1] 8904 0
Attachment [1] 8904 0
Type [2] 8905 0
Informed consent form
Citation [2] 8905 0
Link [2] 8905 0
Email [2] 8905 0
nathaniel.marshall@sydney.edu.au
Other [2] 8905 0
Attachment [2] 8905 0
Type [3] 8906 0
Ethical approval
Citation [3] 8906 0
Link [3] 8906 0
Email [3] 8906 0
nathaniel.marshall@sydney.edu.au
Other [3] 8906 0
Attachment [3] 8906 0
Type [4] 8907 0
Analytic code
Citation [4] 8907 0
Link [4] 8907 0
Email [4] 8907 0
nathaniel.marshall@sydney.edu.au
Other [4] 8907 0
Attachment [4] 8907 0
Summary results
Have study results been published in a peer-reviewed journal?
No
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary