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Trial registered on ANZCTR


Registration number
ACTRN12617000010392
Ethics application status
Approved
Date submitted
15/12/2016
Date registered
4/01/2017
Date last updated
6/03/2019
Date data sharing statement initially provided
6/03/2019
Date results information initially provided
6/03/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
A field survey of windfarm and traffic noise effects on sleep (In-Home Study)
Scientific title
Establishing the physiological and sleep disruption characteristics of wind farm versus traffic noise disturbances in sleep
Secondary ID [1] 289544 0
GNT1113571
Universal Trial Number (UTN)
U1111-1191-1014
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Low frequency noise effects on sleep 299264 0
Condition category
Condition code
Public Health 299268 299268 0 0
Other public health

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Participation in the field measurement protocol will involve two consecutive night recordings. Two nights will help assess repeatability, increase study power and maximise acoustic and sleep recording opportunity. Research personnel including one trained sleep technician and one sound technician, will visit each participant’s home to setup acoustic recording and sleep monitoring equipment (including Electroencephalogram [EEG] and Electrocardiography [ECG]) using already established equipment and methods. As much as is possible, experiments will be scheduled around anticipated worst case traffic/wind farm noise nights based on schedules and weather reports.

Participants' hearing will be tested prior to night 1 of the protocol using an audiometer. To ensure data quality, each evening the research personnel will remain at the participants' home until participants' bedtime and return in the mornings to collect the overnight data. After each night, participants will be asked to rate overall sleep quality and noise relative to their usual sleep. They will collect 5 serial saliva samples immediately upon awakening, over the next 60 min and 12 hours after waking for salivary cortisol (cortisol awakening response) measurements. Hair follicles will also be collected to measure markers of long-term stress. Sleep studies will be scored into sleep stages. They will also be scored for respiratory and arousal events using international standards independent of the acoustic data to assess overall sleep quality (sleep efficiency, wake time after sleep onset, and frequency of arousals). In addition, cardiovascular activation responses, including tachy-bradycardias, pulse wave velocity and pulse wave amplitude attenuation responses will also be examined. All discernible sensory-related activation responses including cardiovascular activation associated with isolated k-complexes, 3-15 sec arousals and full awakenings will be selected for further analysis of event rates per hour of sleep, and noise characteristics preceding each activation event type. Noise will be assessed based on spectral content, overall mean and peak unweighted, A-weighted and G-weighted SPLs and random/periodic variability with time. Full-night quantitative EEG and ECG spectral analyses will also be conducted.
Intervention code [1] 295144 0
Not applicable
Comparator / control treatment
The control group will consist of volunteers from a quiet rural exposure area. They will be determined and selected by an initial survey-based study.
Control group
Dose comparison

Outcomes
Primary outcome [1] 298753 0
Full-night quantitative EEG spectral analyses to measure sleep quality (specifically, sleep efficiency, wake time after sleep onset, and frequency of arousals).
Sleep studies will be sleep staged, scored for respiratory and arousal events using international standards independent of the acoustic data.
Timepoint [1] 298753 0
During each of the two overnight in-home sleep studies.
Primary outcome [2] 298758 0
Full-night quantitative ECG spectral analyses to measure cardiovascular activation responses (including tachy-bradycardias, pulse wave velocity and pulse wave amplitude attenuation responses).
All discernible sensory-related activation responses including cardiovascular activation associated with isolated k-complexes, 3-15 sec arousals and full awakenings will be selected for further analysis of event rates per hour of sleep, and noise characteristics preceding each activation event type.
Timepoint [2] 298758 0
During each of the two overnight in-home sleep studies.
Primary outcome [3] 298759 0
Noise will be assessed on spectral content, overall mean and peak unweighted, A-weighted and G-weighted SPLs and random/periodic variability with time. The noise will be recorded using acoustic recordings that are time-locked with overnight sleep recordings.
Timepoint [3] 298759 0
During each of the two overnight in-home sleep studies.
Secondary outcome [1] 325136 0
Participants' self-rated overall sleep quality relative to their usual sleep will be assessed using an overnight sleep diary with Likert-type scales evaluating sleep quality.
Timepoint [1] 325136 0
At the conclusion of each of the two overnight in-home sleep studies.
Secondary outcome [2] 325137 0
Participants' self-rated overall noise disturbance relative to their usual sleep will be assessed using an overnight sleep diary with Likert-type scales evaluating noise disturbance.
Timepoint [2] 325137 0
At the conclusion of each of the two overnight in-home sleep studies.
Secondary outcome [3] 330363 0
Salivary cortisol levels will be assessed across 5 daily time-points post awakening (i.e., immediately after waking up, 15-, 30-, 45-minutes and 12 hours post awakening).
Timepoint [3] 330363 0
At the conclusion of each of the two overnight in-home sleep studies.

Eligibility
Key inclusion criteria
1. Age: >17 years.
2. Resident in a home in one of the selected survey areas according to overnight noise exposure type and level of complaints. The main aim of the field work is to target wind farm noise exposure communities to recruit:
- highest complaint quartile in wind farm exposure group (WFNQ1).
- lowest quartile complaints in the wind farm exposure group (WFNQ4)

As a secondary aim, we will select separate regionally targeted control groups to recruit participants from:
- traffic noise exposure groups (TNQ1)
- quiet rural exposure control group (CN).
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Language difficulties that might preclude informed consent and study questionnaire completion.

Study design
Purpose
Psychosocial
Duration
Cross-sectional
Selection
Defined population
Timing
Both
Statistical methods / analysis
The primary outcome will be sleep efficiency (sleep time expressed as a percentage of time available for sleep under each noise exposure condition) with the propensity for and magnitude of EEG activation (sub-cortical events, micro-arousals and full-awakenings), arousal thresholds to wind farm versus traffic noise, and cardiovascular responses as key secondary outcomes. Comparisons between groups and conditions will be via linear mixed effects model analyses with night, sleep stage and noise conditions as repeated factors within-subjects, individuals entered as a random effect to account for correlated measures and an overall 2-tailed Type I error rate of 5%. Kaplan-Meier and Cox regression analyses will be used to assess EEG (sub-cortical, micro-arousal and awakening) event-free “survival” to each different noise stimulus type between groups and sleep stages.
Sleep efficiency shows low between subject variability (SD ~10%), large insomnia treatment effects and low within-subject variability over consecutive nights (~3%). We estimate that 15 participants per group has 80% power to detect an 11% (clinically significant) difference in sleep efficiency between groups. An additional 20 participants will be included in the sample size to account for possible drop out rates.

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)
SA

Funding & Sponsors
Funding source category [1] 293926 0
Government body
Name [1] 293926 0
National Health and Medical Research Council
Address [1] 293926 0
Level 1
16 Marcus Clarke Street
Canberra ACT 2601
Country [1] 293926 0
Australia
Primary sponsor type
University
Name
Flinders University
Address
Sturt Rd
Bedford Park
Adelaide, South Australia 5042
Country
Australia
Secondary sponsor category [1] 292751 0
Hospital
Name [1] 292751 0
Repatriation General Hospital
Address [1] 292751 0
Adelaide Institute for Sleep Health
216 Daws Rd
Daw Park
South Australia 5041
Country [1] 292751 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 295344 0
Southern Adelaide Clinical Human Research Ethics Committee (SAC HREC)
Ethics committee address [1] 295344 0
Human Research Ethics, Room 2A
221 Flinders Medical Centre
Level 2, Flinders Medical Centre
BEDFORD PARK SA 5042
Ethics committee country [1] 295344 0
Australia
Date submitted for ethics approval [1] 295344 0
02/06/2016
Approval date [1] 295344 0
20/10/2016
Ethics approval number [1] 295344 0
HREC/16/SAC/207 55.16

Summary
Brief summary
A strong push towards greener and more sustainable energy production has led to rapid expansion of wind farm facilities in Australia and world-wide. This has been associated with wide-spread complaints from neighbouring communities, particularly regarding noise emissions, including “infra-sound” (noise below average hearing threshold), and concerns that this may negatively impact on sleep and health. International studies so far remain inconclusive, particularly regarding noise effects on sleep. However, no studies so far have used physiological recording techniques necessary to properly investigate sleep. Consequently, this study is specifically designed to investigate windfarm noise effects on sleep using measurements normally used to diagnose sleep problems. This field study is the second part of a large three-part project designed to firmly establish what effect windfarm noise has on sleep compared to quiet sleeping conditions (control) and traffic noise, which is already known to disturb sleep and is therefore a useful condition to compare to (positive control).

The overall aim of this study is assess self-reported (subjective) and direct objective measures of sleep quality in the natural home sleep/noise environment to examine relationships between noise, sleep disturbances and other factors.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 66934 0
Prof Peter Catcheside
Address 66934 0
AISH, Flinders University, Level 2, Mark Oliphant Building
5 Laffer Drive, Bedford Park SA 5042
Country 66934 0
Australia
Phone 66934 0
+61 8 72218305
Fax 66934 0
Email 66934 0
peter.catcheside@flinders.edu.au
Contact person for public queries
Name 66935 0
Dr Gorica Micic
Address 66935 0
AISH, Flinders University, Level 2, Mark Oliphant Building
5 Laffer Drive, Bedford Park SA 5042
Country 66935 0
Australia
Phone 66935 0
+61 8 8201 2377
Fax 66935 0
+61 8 8201 2388
Email 66935 0
gorica.micic@flinders.edu.au
Contact person for scientific queries
Name 66936 0
Prof Peter Catcheside
Address 66936 0
AISH, Flinders University, Level 2, Mark Oliphant Building
5 Laffer Drive, Bedford Park SA 5042
Country 66936 0
Australia
Phone 66936 0
+61 8 72218305
Fax 66936 0
Email 66936 0
peter.catcheside@flinders.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
There are ethical and logistical considerations that would prevent IPD sharing. Mechanisms to enable public data sharing for this project do not exist.
What supporting documents are/will be available?
Ethical approval
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?
No
Results – basic reporting
Results – plain English summary