Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12618001913268
Ethics application status
Approved
Date submitted
14/11/2018
Date registered
26/11/2018
Date last updated
10/09/2023
Date data sharing statement initially provided
26/11/2018
Date results information initially provided
10/09/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Low-cost, at home cooling strategies for older adults during hot-and-humid heatwaves.
Scientific title
Assessing the physiological and perceptual efficacy of low cost cooling strategies for older adults in hot and humid heatwaves.
Secondary ID [1] 296583 0
None
Universal Trial Number (UTN)
U1111-1219-1811
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
heat related cardiovascular strain 310392 0
thermal perception (comfort and sensation) 310393 0
Sweating impairments 310394 0
Thermoregulatory strain 312838 0
Heat related cognitive decline 312839 0
Condition category
Condition code
Public Health 309110 309110 0 0
Other public health
Injuries and Accidents 309111 309111 0 0
Other injuries and accidents

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Each participant will take part in four three hour exposures which be randomised;
1. No fan with no skin wetting (comparator)
2. Fan use with no skin wetting
3. No fan use with skin wetting
4. Fan use with skin wetting

They will be asked to sit in a thermally regulated environmental chamber at a temperature of 38°C and 60% relative humidity.

In all fan exposures, participants will be seated 1.25m from an 18" diameter fan with an airflow of ~4.0m/s. This is the velocity of a typical fan at highest speed.

For the skin wetting exposures, approx 770mL, 18ºC tap water will be applied to the skin using a commercially available spray bottle to the face, neck, arms and legs by a researcher.

Additionally, in all exposures they will be given cold (~18ºC) water equivalent to 1ml per kg of body weight every 20 minutes in an attempt to offset dehydration.

There will be a minimum of 72 hours washout between each exposure.
Intervention code [1] 312895 0
Prevention
Comparator / control treatment
No fan with no skin wetting exposure
Control group
Active

Outcomes
Primary outcome [1] 308086 0
Core temperature via rectal thermometer:

Rectal temperature sensor: The participant will be asked to insert a flexible sensor 10-12cm into their rectum. A marker is placed on the sensor using sterile surgical tape. The participant will insert the sensor until the tape reaches their anal surface. The insertion of the sensor may cause some mild discomfort and minor irritation; however, this sensation soon passes. The participant will receive proper instruction regarding the placement of the sensor to ensure their safety and comfort. The participant will be responsible for the insertion of this sensor. It will provide the researcher with an indication of the amount of heat stored in their body and will be tracked throughout the entirety of each experimental session
Timepoint [1] 308086 0
Immediately following the end of exposure
Primary outcome [2] 308088 0
Rate pressure product measured via blood pressure and heart rate at the end of the trial

An automated blood pressure monitor will be strapped to the participants arm and blood pressure will be used by researchers to calculate RPP(heart rate x systolic blood pressure).
Timepoint [2] 308088 0
At the end of exposure
Primary outcome [3] 308092 0
Whole body sweat loss:

The participant will be weighed on a platform scale immediately before and at the completion of the heatwave exposure in order to compare whole-body sweat losses.
Timepoint [3] 308092 0
Immediately following the end of exposure
Secondary outcome [1] 353911 0
Thermal comfort:

The participant will be asked to rate how uncomfortable the heat makes them on a visual analogue scale.
Timepoint [1] 353911 0
Immediately following the end of exposure
Secondary outcome [2] 353919 0
Skin temperature: four skin sensors will be taped to the participants skin surface with hypoallergenic tape. Some hair may need to be shaved (by the use of disposable razors) in order to secure the sensors adequately. These sensors give an indication of skin temperature and dry heat loss from the skin and will be recorded throughout the entirety of each experimental session.
Timepoint [2] 353919 0
Immediately following the end of exposure
Secondary outcome [3] 353921 0
Skin blood flow: A flexible laser probe will measure skin blood flow non-invasively at the upper back and forearm during the entirety of each experimental session.
Timepoint [3] 353921 0
Immediately following the end of exposure
Secondary outcome [4] 353922 0
Local sweat rate:

A small plastic capsule connected to plastic tubing will be placed on the participants upper back and forearm. Dry air is passed through this capsule and a humidity sensor will pick up humidity from the skin and provides a measurement of local sweat rate throughout each experimental session.
Timepoint [4] 353922 0
Immediately following the end of exposure
Secondary outcome [5] 353923 0
Cognitive performance:

The participant will be asked to complete a short-form of the Stroop Colour and Word Test (SCWT) immediately before and at the completion of the heatwave exposure. This test involves them looking at various words and identifying which colour the words are shown in.
Timepoint [5] 353923 0
Immediately following the end of exposure
Secondary outcome [6] 353925 0
Evidence of orthostatic hypotension:

At the completion of the heatwave exposure the participants blood pressure will be taken. They will then be asked to stand up and their blood pressure will be taken after 1 minute of standing and then again after 3 minutes of standing. This test is carried out to see if there is evidence of postural hypotension (a drop in blood pressure within 3 minutes of standing from a seated position).
Timepoint [6] 353925 0
Immediately following the end of exposure
Secondary outcome [7] 353926 0
Thermal sensation:

The participant will be asked to rate how warm they feel on a visual analogue scale during each experimental session.
Timepoint [7] 353926 0
Immediately following the end of exposure
Secondary outcome [8] 353927 0
Heart rate:

Heart rate will be measured using the ECG monitoring system
Timepoint [8] 353927 0
Immediately following the end of exposure
Secondary outcome [9] 353928 0
Blood pressure: An automated blood pressure monitor will be strapped to the participants arm and blood pressure will be taken every 20 minutes. This measure will also enable calculations of mean arterial pressure in combination with HR.
Timepoint [9] 353928 0
Immediately following the end of exposure

Eligibility
Key inclusion criteria
Non smokers (or 1 year since quitting)
Over 60 years of age
Controlled hypertension or healthy older adults
Minimum age
60 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Estrogen therapy
Fluid or electrolyte disorders
Anemia
Abnormal thryoid function
Arrhythmias
Diabetes
Renal disease
Liver disease
Uncontrolled hypertension
Significant cognitive impairment and / or degenerative neurological condition
History of substance abuse
Taking anticholinergic medication
Known atherosclerotic disease
Severe respiratory disease
Known aneurysms
Progressive neurological disorders
Active cancer treatment

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)
Central randomisation via a computer
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Participants will be randomised via a central computer database in a balanced order.
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
The primary research outcomes are change in rate pressure product (RPP), change in rectal temperature (Tre), whole body sweat loss (WBSL) and thermal sensation (TS).

Secondary research outcomes include heart rate (HR), blood pressure (BP), thermal comfort (TC), skin temperature (Tsk).

Tertiary research outcomes include skin blood flow (SkBF), local sweat rate (LSR), cognitive performance, and evidence of orthostatic hypotension (OH).

Data for all trials will be combined with data from our partner site at the Montreal Heart Institute (MHI, ClinicalTrials.gov: NCT03832504) where participants with Coronary Heart Disease are being recruited to make between group comparisons.

Changes from pre- trial to end- 3 hr exposure (using the last 5 min average) will be compared between each intervention and the control (no cooling) trial for all primary variables (i.e., CON vs. Fan, Fan+Skin Wetting, Skin Wetting). To analyse differences, a 2-way mixed effects Analysis of Variance (ANOVA) model will be performed with the repeated factor of intervention (CON vs. Fan, Fan+Skin Wetting, Skin Wetting) and non-repeated factor of group (with and without heart disease). A significant interaction between main effects will be investigated with paired t-tests comparing intervention to CON within each group with post-hot comparisons adjusted with Holm-Bonferroni corrections.

All statistical analyses will be performed with SPSS.

Recruitment
Recruitment status
Stopped early
Data analysis
Data collected is being analysed
Reason for early stopping/withdrawal
Participant recruitment difficulties
Other reasons/comments
Other reasons
We have experienced complications with recruitment and retention following the COVID 19 pandemic and thus have ceased recruitment following enrolment of enough non-hypertensive participants to analyse data.
Date of first participant enrolment
Anticipated
26/11/2018
Actual
30/11/2018
Date of last participant enrolment
Anticipated
28/09/2022
Actual
2/05/2023
Date of last data collection
Anticipated
28/10/2022
Actual
29/05/2023
Sample size
Target
56
Accrual to date
Final
32
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment outside Australia
Country [1] 21019 0
Canada
State/province [1] 21019 0
montreal

Funding & Sponsors
Funding source category [1] 301163 0
Government body
Name [1] 301163 0
National Health and Medical Research Council
Country [1] 301163 0
Australia
Primary sponsor type
University
Name
University of Sydney
Address
The University of Sydney
Camperdown
NSW
2006
Country
Australia
Secondary sponsor category [1] 300784 0
None
Name [1] 300784 0
Address [1] 300784 0
Country [1] 300784 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301908 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 301908 0
Research Integrity & Ethics Administration
Research Portfolio
Level 3, F23 Administration Building
The University of Sydney
NSW
2006
Ethics committee country [1] 301908 0
Australia
Date submitted for ethics approval [1] 301908 0
30/07/2018
Approval date [1] 301908 0
29/08/2018
Ethics approval number [1] 301908 0
2018/496

Summary
Brief summary
This study aims to identify the most appropriate cooling strategy for older adults with and without hypertension during a simulated hot and humid heatwave (38°C and 60% relative humidity)

Research questions:
The primary research question guiding this project is:
1. Are fans and/or skin-wetting effective in decreasing the physiological strain experienced by elderly during a simulated hot, humid heatwave (38°C and 60% relative humidity)

The research hypotheses going into this study are:
1. All interventions will result in reductions in thermal and cardiovascular strain compared to no intervention (control) With fan and skin-wetting (FSW) being the most effective, then no fan and skin-wetting (NFSW), then fan (F), and finally, the control, no-fan (NF).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 88518 0
A/Prof Ollie Jay
Address 88518 0
Thermal Ergonomics Laboratory
Room 901, Susan Wakil Health Building
The University of Sydney, NSW 2006
Country 88518 0
Australia
Phone 88518 0
+61 293519328
Fax 88518 0
Email 88518 0
ollie.jay@sydney.edu.au
Contact person for public queries
Name 88519 0
A/Prof Ollie Jay
Address 88519 0
Thermal Ergonomics Laboratory
Room 901, Susan Wakil Health Building
The University of Sydney, NSW 2006
Country 88519 0
Australia
Phone 88519 0
+61 293519328
Fax 88519 0
Email 88519 0
ollie.jay@sydney.edu.au
Contact person for scientific queries
Name 88520 0
A/Prof Ollie Jay
Address 88520 0
Thermal Ergonomics Laboratory
Room 901, Susan Wakil Health Building
The University of Sydney, NSW 2006
Country 88520 0
Australia
Phone 88520 0
+61 293519328
Fax 88520 0
Email 88520 0
ollie.jay@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?
Individual participant data underlying published results only
When will data be available (start and end dates)?
Immediately following publication - no end date.
Available to whom?
Case-by-case basis at the discretion of the primary sponsor
Available for what types of analyses?
Meta-analysis.
How or where can data be obtained?
Access subject to approvals by the Principal Investigator with a requirement to sign data access agreement.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
243Informed consent form    376365-(Uploaded-14-11-2018-14-26-10)-Study-related document.doc
244Ethical approval    376365-(Uploaded-14-11-2018-14-26-39)-Study-related document.pdf
245Study protocol    376365-(Uploaded-08-05-2019-14-20-54)-Study-related document.docx



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
Dimensions AIElectric fans: A potential stay-at-home cooling strategy during the COVID-19 pandemic this summer?2020https://doi.org/10.1016/j.scitotenv.2020.141180
N.B. These documents automatically identified may not have been verified by the study sponsor.