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Trial registered on ANZCTR

Registration number

ACTRN12619001598178

Ethics application status

Approved

Date submitted

29/10/2019

Date registered

20/11/2019

Date last updated

28/01/2022

Date data sharing statement initially provided

20/11/2019

Type of registration

Prospectively registered

Titles & IDs

Public title

Assessing the health effects of one month of simulated wind farm infrasound: A community-based randomised controlled trial.

Scientific title

Assessing the health effects of one month of simulated wind farm infrasound: A community-based randomised controlled trial

Secondary ID [1]

Australian NH&MRC Targeted Call for Research Grant Grant APP113615

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Sleep Disturbance

Wind Turbine Syndrome

Condition category

Condition code

Neurological

Studies of the normal brain and nervous system

Mental Health

Studies of normal psychology, cognitive function and behaviour

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Participants will be randomised to one of two groups. One group exposed to one month of continuous infrasound speaker exposure and the other group exposed to sham (no sound) speaker exposure. The key exposure of windfarm simulated infrasound at 93dB pK (test exposure) will be generated by specially manufactured speaker boxes which will be placed in each of the participants’ bedrooms and will operate continuously for the duration of the study. Microphones continuously monitor the presence and level of infrasound in the bedroom for the duration of the study.

Intervention code [1]

Other interventions

Comparator / control treatment

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’ bedrooms.

Control group

Placebo

Outcomes

Primary outcome [1]

Changes in wake after sleep onset (WASO) as determined by 4 EEG channel polysomnography with the Alice PDx portable recorder, This will be defined using standard electroencephalography (EEG) based criteria. We will compare the effects of infrasound and sham.

Timepoint [1]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement. The primary timepoint will be the 1 month measurement.

Secondary outcome [1]

Sleep latency (Time to onset of 1st sleep at night as determined by a polysomnography)

Timepoint [1]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement.

Secondary outcome [2]

Sleep Stage Shifts (The total number of sleep stage transitions over the whole night as determined by a polysomnography)

Timepoint [2]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement.

Secondary outcome [3]

Sleep staging (A measure of sleep architecture using the proportions of recorded sleep time that are scored as being stage 1 2 3 or REM sleep as recorded on a polysomnography)

Timepoint [3]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement.

Secondary outcome [4]

Arousal frequency (the Arousal Index is a measure of the number or cortical arousals captured via the EEG on a polysomnography per hour of scored sleep)

Timepoint [4]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement.

Secondary outcome [5]

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]

Single overnight polysomnography study will be measured 1 month after the initial baseline measurement.

Secondary outcome [6]

Sleep parameters measured by actigraphy

Timepoint [6]

At 1 month after the initial baseline measurement.

Secondary outcome [7]

Neurocognitive test (n-back score and Tower of London score)

Timepoint [7]

At 1 month after the initial baseline measurement.

Secondary outcome [8]

Insomnia Severity Index (ISI) score (range: 0 to 28)

Timepoint [8]

At 1 month after the initial baseline measurement.

Secondary outcome [9]

Epworth Sleepiness Scale (ESS) score (range: 0 to 24)

Timepoint [9]

At 1 month after the initial baseline measurement.

Secondary outcome [10]

Noise Annoyance Visual Analog Scale (range: 0 to 10)

Timepoint [10]

At 1 month after the initial baseline measurement.

Secondary outcome [11]

General Health Symptoms Visual Analog Scale (range: 0 to 10)

Timepoint [11]

At 1 month after the initial baseline measurement.

Secondary outcome [12]

Kessler 10 (K10) score (range: 10 to 50)

Timepoint [12]

At 1 month after the initial baseline measurement.

Secondary outcome [13]

Depression, Anxiety and Stress Scale (DASS-21) score (range: 0 to 42 depression, anxiety and stress)

Timepoint [13]

At 1 month after the initial baseline measurement.

Secondary outcome [14]

Warwick Edinburgh Mental Wellbeing Scale score (range: 14 to 70)

Timepoint [14]

At 1 month after the initial baseline measurement.

Secondary outcome [15]

Anthropometric measures - Body Mass Index by portable stadiometer for the height component and by portable digital scale for the weight component

Timepoint [15]

At 1 month after the initial baseline measurement.

Secondary outcome [16]

Blood Pressure (mmHg) by portable digital self-inflating sphygmomanometer

Timepoint [16]

Average of 3 measurements taken at 1 month after the initial baseline measurement.

Secondary outcome [17]

Arterial Stiffness - Pulse Wave Velocity (m/s)

Timepoint [17]

At 1 month after the initial baseline measurement.

Eligibility

Key inclusion criteria

1. Aged 18 or above
2. Noise sensitive individuals -defined as Weinstein’s Noise Sensitivity Scale (WNS) Score >58 (which was the median score in a reported study)
3. Normal hearing based on phone questionnaire
4. Regular sleep of minimum 5.5 hours / 24 hours for 7 days as demonstrated by 1 week of actigraphy
5. Fluent in English, to be able to answer computerised questionnaires and undergo neurocognitive assessments in English

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

1. Rotating shift worker
2. Planning to be away from home during the study period
3. Major psychiatric disorders
4. Use of any hypnotic medications or other medications that interfere with sleep within the last month
5. Anyone in the household pregnant or breastfeeding or planning to during the study period
6. Children younger than 5 years of age living or regularly spending time in the home.

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. Screening of suitable participants will be undertaken in three phases. The first phase will be done over the phone to check if the participant has normal hearing and does not wear a hearing aid. The second phase will be conducted via an online screening questionnaire. The third phase will combine a non- invasive technique (wrist actigraphy and sleep diary) for the at-home measurement of normal sleep/wake cycles.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Participants will be assigned the type of exposure (infrasound speaker or sham speaker) in a random order. A statistician who assists the Data Safety Monitoring Board (DSMB) and who will never meet any participant or play role in selection or testing of participants has computer generate the randomisation list in blocks of 12, with 12 blocks of 12 = 144 randomisation numbers..

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

Parallel

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.

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. As multiple outcome measures will be made (at baseline and at 1 month follow-ups) a “time” fixed effect will also be included and exposure-by- time interactions will be tested. The differences specifically at the 1 month time period will be the primary endpoint. In sub-analyses we will also test whether changes in outcomes are influenced by whether people thought windfarms have health effects (expectancy) to establish whether this attribute modifies the propensity to experience WTS symptoms with exposure.

Recruitment

Recruitment status

Recruiting

Date of first participant enrolment

Anticipated

25/11/2019

Actual

9/12/2019

Date of last participant enrolment

Anticipated

1/06/2022

Actual

Date of last data collection

Anticipated

30/06/2022

Actual

Sample size

Target

120

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

NSW

Funding & Sponsors

Funding source category [1]

Government body

Name [1]

NHMRC

Address [1]

GPO Box 1421 Canberra ACT 2601

Country [1]

Australia

Primary sponsor type

Other

Name

Woolcock Institute of Medical Research

Address

431 Glebe Point Road Glebe 2037
NSW

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Sydney Local Health District Ethics Review Committee (Royal Prince Alfred Hospital Zone)

Ethics committee address [1]

Research Development Office Royal Prince Alfred Hospital Missenden Road Camperdown NSW 2050

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

09/07/2019

Approval date [1]

24/07/2019

Ethics approval number [1]

X17-0235 and HREC/17/RPAH/351

Summary

Brief summary

The study hypothesis is that exposure to infrasound, compared with the sham exposure, is associated with impaired sleep quality.
We will randomly allocate participants to one of two groups. One group will receive speakers that generate wind farm simulated infrasound and the other group will receive speakers that generate no sound (sham). The speakers will be installed in the bedroom, will operate continuously and remain in place for 1 month.
In addition, to impairment of sleep quality we will assess whether six months exposure to wind farm simulated infrasound is associated with other health effects such as annoyance, impaired neurobehavioural and neurocognitive performance, impaired vestibular function, increased arterial stiffness, increased blood pressure, mood, anxiety and stress. Secondly, to investigate whether experiencing an excess of symptoms that have been attributed to Wind Turbine Syndrome is related to baseline levels of stress and anxiety.

Trial website

https://www.windfarmstudy.com

Trial related presentations / publications

Public notes

This application mirrors that which was previously approved by the ANZCTR with number ACTRN12619000027112.  We have had to revise the protocol from 6 month exposure to 1 month exposure because we could not recruit participants for the study.  Otherwise the study is identical.

Contacts

Principal investigator

Name

Prof Guy Marks

Address

Woolcock Institute of Medical Research 431 Glebe Point Road
Glebe
NSW 2037

Country

Australia

Phone

+61 2 9114 4066

Fax

+61 2 9114 0011

[email protected]

Contact person for public queries

Name

Brett Toelle

Address

Woolcock Institute of Medical Research 431 Glebe Point Road
Glebe
NSW 2037

Country

Australia

Phone

+61 2 9114 4062

Fax

+61 2 9114 0011

[email protected]

Contact person for scientific queries

Name

Brett Toelle

Address

Woolcock Institute of Medical Research 431 Glebe Point Road
Glebe
NSW 2037

Country

Australia

Phone

+61 2 9114 4062

Fax

+61 2 9114 0011

[email protected]

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

Yes

What data in particular will be shared?

Deidentified individual participant data collected during the trial

When will data be available (start and end dates)?

Data will be available from date of publication of the main report and for 10 years from the date of publication.

Available to whom?

Researchers who provide a scientifically valid and ethically approved protocol

Available for what types of analyses?

Available for analyses contained within an ethically approved protocol

How or where can data be obtained?

Data will be provided to the researcher directly by the Principal Investigator, Professor Guy Marks subject to receipt of the ethics approval and the ethically approved protocol. Email Address: [email protected]

What supporting documents are/will be available?

Doc. No.	Type	Other Details	Attachment
4299	Study protocol	ANZCTR	378249-(Uploaded-23-10-2021-13-18-25)-Study-related document.pdf
4300	Informed consent form		378249-(Uploaded-23-10-2021-13-21-28)-Study-related document.pdf
4301	Ethical approval		378249-(Uploaded-29-10-2019-14-27-04)-Study-related document.pdf

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically