ANZCTR - Registration

Please note the ANZCTR will be unattended from Friday 20 December 2019 for the holidays. The Registry will re-open on Tuesday 07 January 2020. Submissions and updates will not be processed during that time.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers

Trial registered on ANZCTR

Registration number

ACTRN12619000938101

Ethics application status

Approved

Date submitted

25/06/2019

Date registered

5/07/2019

Date last updated

5/07/2019

Date data sharing statement initially provided

5/07/2019

Type of registration

Prospectively registered

Titles & IDs

Public title

Low-cost, at home cooling strategies for older adults during hot-and-dry heatwaves

Scientific title

Assessing the physiological and perceptual efficacy of low cost cooling strategies for older adults in hot-and-dry heatwaves.

Secondary ID [1]

None

Universal Trial Number (UTN)

U1111-1235-7682

Trial acronym

Linked study record

Health condition

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

Heat related cardiovascular strain

Thermal perception (comfort and sensation)

Sweating impairments

Thermoregulatory strain

Heat-related cognitive decline

Condition category

Condition code

Injuries and Accidents

Other injuries and accidents

Public Health

Other public health

Cardiovascular

Normal development and function of the cardiovascular system

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Intervention

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 45°C and 15% 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 exposure, moisture (tap water ~18 degrees) will be applied using a damp cloth every 20 minutes to the forehead, 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]

Prevention

Comparator / control treatment

No fan with no skin wetting exposure

Control group

Active

Outcomes

Primary outcome [1]

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]

Immediately following the end of exposure

Primary outcome [2]

Rate pressure product measured via blood pressure and heart rate

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]

Immediately following the end of exposure

Primary outcome [3]

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]

Immediately following the end of exposure

Secondary outcome [1]

Thermal comfort

The participant will be asked to rate how uncomfortable the heat makes them on a visual analogue scale

Timepoint [1]

Immediately following the end of exposure

Secondary outcome [2]

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]

Immediately following the end of exposure

Secondary outcome [3]

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]

Immediately following the end of exposure

Secondary outcome [4]

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]

Immediately following the end of exposure

Secondary outcome [5]

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]

Immediately following exposure

Secondary outcome [6]

Evidence of orthostatic hypotension

At the half way stage of each exposure (1 hour and 30 minutes) and 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]

Immediately following the end of exposure

Secondary outcome [7]

Thermal sensation

The participant will be asked to rate how warm they feel on a visual analogue scale during each experimental session.

Timepoint [7]

Immediately following the end of exposure

Secondary outcome [8]

Heart rate

Heart rate will be measured using a 12 lead ECG monitoring system

Timepoint [8]

Immediately following the end of exposure

Secondary outcome [9]

Blood pressure

Blood pressure: An automated blood pressure monitor will be strapped to the participants arm and duplicate blood pressure measurements will be taken every 20 minutes. This measure will also enable calculations of mean arterial pressure in combination with HR.

Timepoint [9]

Immediately following the end of exposure

Eligibility

Key inclusion criteria

Non smokers (or at least 1 year since quitting)
Over 60 years of age
Controlled hypertension or healthy older adult

Minimum age

60 Years

Maximum age

No limit

Gender

Both males and females

Can healthy volunteers participate?

Yes

Key exclusion criteria

Oestrogen therapy
Fluid or electrolyte disorders
Anaemia
Abnormal thyroid 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 of males and females and participants with hypertension and no hypertension

Phase

Not Applicable

Type of endpoint(s)

Efficacy

Statistical methods / analysis

The primary research outcomes for this study are change in rectal temperature (Tre) and rate pressure product (RPP),

Secondary outcomes include; heart rate (HR), blood pressure (BP), thermal sensation (TS), thermal comfort (TC), whole-body sweat losses (WBSL), skin temperature (TSk), skin blood flow (SkBF), local sweat rate (LSR), cognitive performance, and evidence of orthostatic hypotension (OH).

All data will be compared between all four interventions.

To assess the primary and secondary outcome variables, pre to post trial changes as well as the means of the dependent variables will be analyzed using one-way repeated measures ANOVAs with the repeated factor of cooling intervention (four levels: no fan (NF), fan (F), fan and skin-wetting (FSW), and no fan and skin-wetting (NFSW)).

If significant main effects or interactions are found, independent differences will be assessed using a two-tailed paired Student’s t-tests while maintaining a fixed probability (5%) of making a type I error using a Holm-Bonferroni correction.

All statistical analyses will be performed with GraphPad Prism (version 6.0, GraphPad Software, La Jolla, CA).

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

15/07/2019

Actual

Date of last participant enrolment

Anticipated

28/09/2022

Actual

Date of last data collection

Anticipated

28/10/2022

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

NSW

Recruitment outside Australia

Country [1]

Canada

State/province [1]

Montreal

Funding & Sponsors

Funding source category [1]

Government body

Name [1]

National Health and Medical Research Council

Address [1]

16 Marcus Clarke St
Canberra
ACT
2601

Country [1]

Australia

Primary sponsor type

University

Name

University of Sydney

Address

The University of Sydney
Camperdown
NSW
2006

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

The University of Sydney Human Research Ethics Committee

Ethics committee address [1]

Research Integrity & Ethics Administration
Research Portfolio
Level 3, F23 Administration Building
The University of Sydney
NSW
2006

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

30/07/2018

Approval date [1]

29/08/2018

Ethics approval number [1]

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 dry heatwave (45°C and 15% 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, dry heatwave (45°C and 15% 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

A/Prof Ollie Jay

Address

Room 216
K Block
The University of Sydney
NSW
2006

Country

Australia

Phone

+61 293519328

Fax

ollie.jay@sydney.edu.au

Contact person for public queries

Name

A/Prof Ollie Jay

Address

Room 216
K Block
The University of Sydney
NSW
2006

Country

Australia

Phone

+61 293519328

Fax

ollie.jay@sydney.edu.au

Contact person for scientific queries

Name

A/Prof Ollie Jay

Address

Room 216
K Block
The University of Sydney
NSW
2006

Country

Australia

Phone

+61 293519328

Fax

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 Principle Investigator with a requirement to sign data access agreements

What supporting documents are/will be available?

Study protocol
Informed consent form
Ethical approval

How or where can supporting documents be obtained?

Type [1]

Informed consent form

Citation [1]

Link [1]

Email [1]

Other [1]

Attachment [1]

http://www.anzctr.org.au/Steps11and12/377830-(Uploaded-20-06-2019-14-57-52)-Study-related document.doc

Type [2]

Ethical approval

Citation [2]

Link [2]

Email [2]

Other [2]

Attachment [2]

http://www.anzctr.org.au/Steps11and12/377830-(Uploaded-20-06-2019-14-58-37)-Study-related document.pdf

Type [3]

Study protocol

Citation [3]

Link [3]

Email [3]

Other [3]

Attachment [3]

http://www.anzctr.org.au/Steps11and12/377830-(Uploaded-20-06-2019-15-17-16)-Study-related document.docx

Summary results

No Results

Trial Review