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Trial registered on ANZCTR


Registration number
ACTRN12615000964516
Ethics application status
Approved
Date submitted
30/08/2015
Date registered
15/09/2015
Date last updated
11/12/2018
Date data sharing statement initially provided
11/12/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
The six minute walk test in pregnant women and in women of childbearing age – a reference range study
Scientific title
The six minute walk test in pregnant women and in women of childbearing age – a reference range study
Secondary ID [1] 287373 0
nil
Universal Trial Number (UTN)
U1111-1173-7990
Trial acronym
6MWT
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Pregnancy 296057 0
Condition category
Condition code
Cardiovascular 296323 296323 0 0
Normal development and function of the cardiovascular system
Public Health 296381 296381 0 0
Health service research

Intervention/exposure
Study type
Observational
Patient registry
True
Target follow-up duration
0
Target follow-up type
Hours
Description of intervention(s) / exposure
The Six Minute Walk (6MWT) Test, conducted as specified by the National Heart Foundation of Australia, with two walk tests performed and this should take a maximum of 30 min to complete including the breaks.

The Incremental Shuttle Walk Test conducted as specified by "Holland AE, Spruit MA, Troosters T, et al. An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease. Eur Respir J 2014;44:1428-46." This test will take approximately 30 minutes and be conducted one-on-one by one of the trained research investigators (including a physiotherapist or trained research midwife).

Transthoracic echocardiography according to guidelines by the American Society of Echocardiography. This test will take approximately 15 minutes and be conducted one-on-one by one of the trained research investigators (including a trained obstetric anaesthetist (TTE trained) or cardiac sonographer).

Cardiopulmonary exercise testing (CPET) according to accepted guidelines "American Thoracic S, American College of Chest P. ATS/ACCP Statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003;167:211-77." This test will take approximately 1 hour and will be conducted using a stationary bicycle (cycle ergometer), one-on-one with the trained research and clinical team at Peter MacCallum Hospital.

Testing will occur over two separate days and will be conducted in women in the early pregnancy group of participants in the 6MWT study (healthy nulliparous pregnant women approximately less than 24 weeks gestation, no musculoskeletal problems, no pelvic floor problems – all outpatients). The two testing days are to occur within a seven-day period. On the first testing day participants will complete three of four tests.
Day One:
Resting echocardiography – Royal Women’s Hospital
The Minute Walk Test (6MWT) - Royal Women’s Hospital
Cardiopulmonary Exercise Testing (CPEP) – Peter MacCallum Cancer Centre
Day Two:
Perform the Incremental Shuttle walk Test (ISWT) – Royal Women’s Hospital

Selection of participants
Testing will be conducted in women in the early pregnancy group of participants in the 6MWT study (healthy nulliparous pregnant women approximately less than 24 weeks gestation, no musculoskeletal problems, no pelvic floor problems – all outpatients). Therefore, we will recruit women from this group of participants.
A convenience sample of 100 clinicians (obstetricians, obstetric trainees and midwifes) will be invited to participate in a questionnaire regarding the assessment and management of breathlessness and exertion in pregnant women (a scenario will be presented of a hypothetical primaparous woman at 30 weeks’ gestation). Objective scales - modified Borg Dyspnoea Scale (BDS) and the rating of Perceived exertion scale (RPE) will be used to numerically score clinicians grading of breathlessness and exertion.
Intervention code [1] 292718 0
Not applicable
Comparator / control treatment
N/A
Control group
Uncontrolled

Outcomes
Primary outcome [1] 295977 0
This will be metres walked in six minutes (average of two tests with a 15 minute break to allow for return to baseline values – this will be confirmed by return to baseline heart rate).
Timepoint [1] 295977 0
At the end of the second six minute walk test completion
Secondary outcome [1] 317085 0
Blood pressure (BP) measured by automatic blood pressure device
Timepoint [1] 317085 0
At the beginning and the end of the second six minute walk test
Secondary outcome [2] 317277 0
Oxygen saturation (SpO2) measured by a pulse oximeter
Timepoint [2] 317277 0
At the beginning and the end of the six minute walk test
Secondary outcome [3] 317278 0
Heart rate measured by the pulse oximeter
Timepoint [3] 317278 0
At the beginning and the end of the six minute walk test
Secondary outcome [4] 317279 0
Rating of Perceived Exertion (RPE) Category Scale (actual and expected) measured by answering questions to a structured questionnaire - National Heart Foundation of Australia
Timepoint [4] 317279 0
At the end of the six minute walk test
Secondary outcome [5] 317280 0
Numerical value on dyspnoea scale (actual and expected) National Heart Foundation of Australia
Timepoint [5] 317280 0
At the end of the six minute walk test
Secondary outcome [6] 317281 0
Respiratory rate measured by counting the participants respiratory rate in 20 seconds and multiplying by 3
Timepoint [6] 317281 0
At the beginning and end of the 6 minute walk test
Secondary outcome [7] 342588 0
Distance walked in the incremental shuttle walk test.
.
Timepoint [7] 342588 0
at the end of the test
Secondary outcome [8] 342589 0
Cardiac output obtained by transthoracic echocardiography.
.
Timepoint [8] 342589 0
At rest before exercise testing
Secondary outcome [9] 342590 0
maximal oxygen utilisation capacity (VO2Max) obtained by CardioPulmonary Exercise Testing (CPET).
Timepoint [9] 342590 0
At the end of CPET testing

Eligibility
Key inclusion criteria
Healthy pregnant nulliparous women will be defined as American Society of Anesthesiologists (ASA) Classification I or II, with no significant medical or surgical illnesses, and aged 18 - 40 years. Second trimester women will be recruited from 140 to 236 weeks gestation. Term pregnant women will be recruitment from 360 weeks gestation until delivery. Healthy non-pregnant nulliparous women will be defined as American Society of Anesthesiologists (ASA) Classification I or II, with no significant medical or surgical illnesses, and aged 18 - 40 years.
a. Women less than 24 weeks pregnant will be included if body mass index is less than or equal to 32 kg/m2 at the time of the study
b. Women equal to or greater than 36 weeks pregnant will be included if body mass index is less than 35 kg/m2 at the time of the study
c. Non-pregnant women will be included if body mass index is equal to or less than 30 kg/m2 at the time of the study
Minimum age
18 Years
Maximum age
40 Years
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Any woman with pre-existing conditions that limit ability to exercise (joint, muscle, bone, neurological), pre-existing or gestational diabetes, pre-existing or pregnancy acquired cardiovascular disease, multiple pregnancy, smokers, any woman in labour or postpartum and inability to consent to study.

a. Women less than 24 weeks pregnant will be excluded if body mass index is greater than 32 kg/m2 at the time of the study
b. Women equal to or greater than 36 weeks pregnant will be excluded if body mass index equal to or greater than 35 kg/m2 at the time of the study
c. Non-pregnant women will be excluded if body mass index is greater than 30 kg/m2 at the time of the study


Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
Data presentation and analysis: Demographic and obstetric data will be displayed as mean and standard deviation, median with interquartile ranges, or number and percentage as appropriate. Total distance walked and secondary end-points will be presented as mean and standard deviation and range.
Sample size: Regarding the sample size there are so few patients in the 20-40 age group in published studies and only one pregnancy study of 37 patients we have not performed a sample size calculation. We do not aim to compare the groups in this study. We aim to generate three independent sets of data and reference ranges.
A convenience sample of 30 women will undergo the Six Minute Walk test, the incremental shuttle walk test, cardiopulmonary exercise testing and echocardiography. The reason to do this is to determine the relationship between submaximal exercise testing with exercise tests (The Six Minute Walk Test - an unpaced test, and the Incremental Shuttle Walk Test - a paced test) and cardiac function with echocardiography and direct measurement of maximal oxygen utilisation capacity with the cardiopulmonary exercise testing.

Recruitment
Recruitment status
Recruiting
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)
VIC
Recruitment hospital [1] 4274 0
The Royal Women's Hospital - Parkville
Recruitment hospital [2] 9907 0
Peter MacCallum Cancer Centre - Melbourne
Recruitment postcode(s) [1] 18714 0
3000 - Melbourne
Recruitment outside Australia
Country [1] 7126 0
United Kingdom
State/province [1] 7126 0
London
Country [2] 7154 0
South Africa
State/province [2] 7154 0
Cape Town

Funding & Sponsors
Funding source category [1] 291935 0
Hospital
Name [1] 291935 0
The Royal Women's Hospital
Address [1] 291935 0
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Country [1] 291935 0
Australia
Funding source category [2] 298540 0
Other Collaborative groups
Name [2] 298540 0
Australian and New Zealand College of Anaesthestists
Address [2] 298540 0
PO Box 6095,
Melbourne, Victoria 3004,
Australia
Country [2] 298540 0
Australia
Primary sponsor type
Hospital
Name
The Royal Women's Hospital
Address
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Country
Australia
Secondary sponsor category [1] 290604 0
Hospital
Name [1] 290604 0
Chelsea & Westminster Hospital
Address [1] 290604 0
369 Fulham Rd, London SW10 9NH UK
Country [1] 290604 0
United Kingdom
Other collaborator category [1] 278604 0
Hospital
Name [1] 278604 0
Mowbray Maternity Hospital
Address [1] 278604 0
12 Hornsey Rd, Mowbray
Cape Town, 7700, South Africa
Country [1] 278604 0
South Africa
Other collaborator category [2] 279923 0
Hospital
Name [2] 279923 0
Peter MacCallum Cancer Centre
Address [2] 279923 0
305 Grattan St, Melbourne VIC 3000
Country [2] 279923 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 293436 0
The Royal Women's Hospital Human Research Ethics Committee (EC00259)
Ethics committee address [1] 293436 0
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Ethics committee country [1] 293436 0
Australia
Date submitted for ethics approval [1] 293436 0
02/09/2015
Approval date [1] 293436 0
26/10/2015
Ethics approval number [1] 293436 0

Summary
Brief summary
This international multicentre prospective observational study, performed at the Royal Women’s Hospital, Melbourne, Australia, and Chelsea & Westminster Hospital, London, UK, and Mowbray Maternity Hospital, Cape Town, South Africa aims to determine the reference range for an exercise test, the six minute walk test, in healthy pregnant women and non-pregnant women of childbearing age. This test is commonly used in non-pregnant adults to determine cardiovascular fitness and as a prognostic test in adults with chronic medical conditions. Its utility has not been investigated in pregnant women. It is hoped that this study will provide the baseline data for further studies investigating the usefulness of this test in pregnant women and non-pregnant women of childbearing age. Specifically, the use of this test to predict women who will develop new onset hypertension in pregnancy, the use of this test as part of a pre-pregnancy exercise intervention program to reduce the likelihood of developing new onset hypertension in pregnancy, and the use of the test to quantify symptoms of fatigue and breathlessness in pregnancy.
As part of this study 30 pregnant women in second trimester will undergoing three additional test - the incremental shuttle walk test, cardiopulmonary exercise testing and transthoracic echocardiography. The reason to do this is to determine the relationship between submaximal exercise testing with exercise tests (The Six Minute Walk Test - an unpaced test, and the Incremental Shuttle Walk Test - a paced test) and cardiac function with echocardiography and direct measurement of maximal oxygen utilisation capacity with the cardiopulmonary exercise testing.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 59922 0
A/Prof Alicia Dennis
Address 59922 0
The Royal Women’s Hospital,
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Country 59922 0
Australia
Phone 59922 0
+61 3 8345 2000
Fax 59922 0
Email 59922 0
alicia.dennis@thewomens.org.au
Contact person for public queries
Name 59923 0
A/Prof Alicia Dennis
Address 59923 0
The Royal Women’s Hospital,
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Country 59923 0
Australia
Phone 59923 0
+61 3 8345 2000
Fax 59923 0
Email 59923 0
alicia.dennis@thewomens.org.au
Contact person for scientific queries
Name 59924 0
A/Prof Alicia Dennis
Address 59924 0
The Royal Women’s Hospital,
Locked Bag 300, Corner Grattan Street and Flemington Road, Parkville, Victoria, Australia 3052
Country 59924 0
Australia
Phone 59924 0
+61 3 8345 2000
Fax 59924 0
Email 59924 0
alicia.dennis@thewomens.org.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
Summary results
No Results