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Trial registered on ANZCTR


Registration number
ACTRN12614000020684
Ethics application status
Approved
Date submitted
14/11/2013
Date registered
8/01/2014
Date last updated
3/08/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of a novel floor-based dome device on lower limb haemodynamics of seated individuals
Scientific title
Randomised controlled trial, of healthy 18-65 year old subjects randomised to use their left or right foot on floor-based dome device, comparing the venous haemodynamics of the dome-mobilised limb and the non-mobilised limb.
Secondary ID [1] 283593 0
Nil
Universal Trial Number (UTN)
U1111-1150-3421
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Venous thromboembolism 290513 0
Condition category
Condition code
Blood 290902 290902 0 0
Clotting disorders
Cardiovascular 290923 290923 0 0
Diseases of the vasculature and circulation including the lymphatic system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Change in protocol re timing of measurement of blood flow by ultrasound - which is now as follows:

Floor- based footrest. This is a small device, approx 300mm in length, with two raised domes. Viewed from the front it looks like the letter m. The participant flexes and extends the plantar portion of the sole of their foot over the dome to promote venous blood return through compression of the venous plexus in the sole of the foot.

For this study, participants will be asked to sit on an apporpriately adjusted chair so that their feet rest flat on the floor with their knees at 120 degrees (measured by a goniometer).

They will remain in this position until time 10 minutes when basline ultrasound measures of popliteal venous flow will be done.

Then at time points 14 and 18 minutes, they will be asked to flex and extend the sole of one foot (selected by pre-prepared randomisation programme) over the dome device for 60 seconds. Two ultrasound measurements at the popliteal vein will be done in the mobilising leg while it is mobilising, and two measures of popliteal flow will be done in the immobile leg immediately after.

The study will be deemed to be completed after the measures that start at the 18 minute time point.
Intervention code [1] 288281 0
Prevention
Comparator / control treatment
Non-mobilisation of contralateral limb. it will remain flat on the platform while they use the floor-based device on with their randomised foot.
Control group
Active

Outcomes
Primary outcome [1] 290888 0
Peak systolic Velocity (cm/sec) at the popliteal vein in the dome-mobilised limb versus the non-mobilised limb as measured by doppler ultrasound under use of trained ultrasonographers
Timepoint [1] 290888 0
14 minutes
Secondary outcome [1] 305539 0
Peak systolic flow velocity (cm/s) in the popliteal vein of both the dome-mobilised and immobile leg as measured by doppler ultrasound under use of trained ultrasonographers
Timepoint [1] 305539 0
10 and 18 minutes
Secondary outcome [2] 305540 0
Mean flow velocity (cm/s), in the popliteal vein of both the dome-mobilised and immobile leg as measured by doppler ultrasound under use of trained ultrasonographers.
The test will be undertaken using doppler ultrasound.
Timepoint [2] 305540 0
10, 14 and 18 minutes
Secondary outcome [3] 305541 0
Vein diameter (mm)in the popliteal vein of both the dome-mobilised and immobile leg as measured by doppler ultrasound under use of trained ultrasonographers
The test will be undertaken using doppler ultrasound.
Timepoint [3] 305541 0
10, 14 and 18 minutes
Secondary outcome [4] 305542 0
Total volume flow (L/s) in the popliteal vein of both the dome-mobilised and immobile leg as measured by doppler ultrasound under use of trained ultrasonographers.
The test will be undertaken using doppler ultrasound.
Timepoint [4] 305542 0
10,14 and 18 minutes

Eligibility
Key inclusion criteria
Able to provide informed consent
Aged between 18 and 65 years
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. History of previous or current deep vein thrombosis
2. Pregnancy (this may alter lower limb venous return from compression at the level of the iliac vein)
3. History or clinical features of peripheral vascular disease (including arterial and venous insufficiency), or other lower limb abnormalities, such as peripheral neuropathy, scleroderma, lymphoedema, or joint deformity from inflammatory arthritis

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)
Subjects will be assessed to ensure they meet the inclusion / exclusion criteria, and for infomred consent. They will be randomised on a 1:1 basis to use the floor-based dome device with either their left or right foot whiel keeping the contra-lateral foot still.
Randomisation will be provided via randomisation programme run by biostatistitian.
Allocation concealment of randomisation will be by sealed, opaque envelopes which will be opened by the study coordinatros after the subject has provided informed consent and is deemed to have met all inclusion / exclusion criteria
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation will be provided via randomisation programme run by biostatistitian.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
We anticipate that use of the dome device will achieve a performance similar to that of the Micro-mobile foot compression device used in a previous study. The Micro-mobile device achieved a change from baseline blood flows in an immobile limb of approx 15cm/s. This study is designed to assess whether the dome device can achieve a change in blood flow that is within 5cm/s of the lower flow limit for micro-mobile compression device.

Using a paired SD of 7.49cm/s for the paired change from baseline 60 minute peak systolic flow, as seen in the micro-mobile study, a sample size of 10 participants has at least 90% power with a one sided alpha of 5% to rule out a difference from baseline of less than 8cm/s.


The primary outcome variable analysis will be a mixed linear model comparing the peak systolic blood flow between legs adjusted for baseline flow as a co-variate. For the primary outcome variable analysis P=0.05 will be used to assess statistical significance.

For exploratory purposes paired t-tests will compare the outcome variables for the mobile and immobile leg at each time point separately, and also for the change from baseline. No adjustment for multiple statistical testing will be used for the secondary outcome variables and analyses.

A mixed linear model will be used to estimate the overall difference between the two interventions, the effect of time, and whether there is an interaction between interventions and the effect of time.

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 outside Australia
Country [1] 5624 0
New Zealand
State/province [1] 5624 0
Wellington

Funding & Sponsors
Funding source category [1] 288273 0
Charities/Societies/Foundations
Name [1] 288273 0
Medical Research Institute of New Zealand (MRINZ)
Address [1] 288273 0
Level 7, CSB Building
Wellington Regional Hospital
Riddiford Street
Newtown
Wellingon 6021
Country [1] 288273 0
New Zealand
Primary sponsor type
University
Name
Victoria University of Wellington
Address
School of Biological Sciences
Victoria University of Wellington
PO Box 600
Wellington 6140
New Zealand
Country
New Zealand
Secondary sponsor category [1] 286988 0
None
Name [1] 286988 0
Address [1] 286988 0
Country [1] 286988 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290170 0
Victoria University Human ethics committee
Ethics committee address [1] 290170 0
School of Biological Sciences
Victoria University of Wellington
PO Box 600
Wellington 6140
New Zealand
Ethics committee country [1] 290170 0
New Zealand
Date submitted for ethics approval [1] 290170 0
13/11/2013
Approval date [1] 290170 0
08/04/2014
Ethics approval number [1] 290170 0

Summary
Brief summary
Blood flow in the veins of the legs usually slows down when a person sits for a period of time. This study is designed to see if blood flow in the veins can be improved by using a small foot rest that encourages people to compress their foot on it intermittently. This may help reduice the incidence of blood clots in legs that can occur with protracted periods of sitting.
Trial website
Trial related presentations / publications
This study has been selected for publication in the December Release of Occupational Ergonomics in December 2015, which has not yet been formally released.:
Braithwaite I, Mackintosh S, Mallon A, Weatherall M, Beasley R. Legflow (Registered Trademark) increases lower-limb haemodynamics when seated: a randomised controlled trial. (Occupational Ergonomics: awaiting confirmation of journal reference on formal publication release)
Public notes

Contacts
Principal investigator
Name 44322 0
Dr Irene Braithwaite
Address 44322 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 44322 0
New Zealand
Phone 44322 0
+64 4 805 0245
Fax 44322 0
+64 4 389 5707
Email 44322 0
irene.braithwaite@mrinz.ac.nz
Contact person for public queries
Name 44323 0
Dr Irene Braithwaite
Address 44323 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 44323 0
New Zealand
Phone 44323 0
+64 4 805 0245
Fax 44323 0
+64 4 389 5707
Email 44323 0
irene.braithwaite@mrinz.ac.nz
Contact person for scientific queries
Name 44324 0
Dr Irene Braithwaite
Address 44324 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 44324 0
New Zealand
Phone 44324 0
+64 4 805 0245
Fax 44324 0
+64 4 389 5707
Email 44324 0
irene.braithwaite@mrinz.ac.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary