Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12607000621415
Ethics application status
Approved
Date submitted
3/12/2007
Date registered
5/12/2007
Date last updated
29/06/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
A study to investigate the effect of an ergonomic seat on blood flow in the lower legs.
Scientific title
A randomised controlled trial to investigate the effect of an ergonomic seat on lower limb venous blood flow.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Deep vein thrombosis 2331 0
Condition category
Condition code
Other 2433 2433 0 0
Research that is not of generic health relevance and not applicable to specific health categories listed above

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Venous blood flow will be measured after subjects have lain prone for 5 minutes (baseline; time (T) = 5). They will then be randomly allocated to sit first in either the intervention chair (the ergoCentric ergonomic chair) or the control chair. Venous blood flow will be measured again after subjects have sat in the ergoCentric ergonomic chair with their legs at a 90 degree angle for 5 minutes and then when they have sat with their legs at a 120 degree angle for 5 minutes. (T = 10 and T =15 respectively). The total time subjects will spend seated in the ergoCentric ergonomic chair will be 10 minutes. The subjects will then lie prone for 5 minutes to re-establish the baseline blood flow rate which will be measured at T=20 and they will then cross over to the control treatment (i.e. there will be a 5 minute period during which time subjects will lie prone before they crossover to the control). Blood flow measurement is not continuous but will occur after the subject has spent 5 minutes in each posture.
Intervention code [1] 2048 0
Prevention
Comparator / control treatment
Venous blood flow will be measured after subjects have lain prone for 5 minutes (baseline). It will be measured again after subjects have sat in the Herman Miller Aeron chair (the control chair) with their legs at a 90 degree angle for 5 minutes and then when they have sat with their legs at a 120 degree angle for 5 minutes. The total time seated in the Herman Miller Aeron chair will be 10 minutes. Blood flow measurement is not continuous but will occur after the subject has spent 5 minutes in each posture.
Control group
Active

Outcomes
Primary outcome [1] 3331 0
Popliteal vein peak systolic velocity measured by Doppler Ultrasound
Timepoint [1] 3331 0
T = 5, 10, 15, 20, 25 and 30 min
Secondary outcome [1] 5543 0
Mean popliteal vein flow velocity measured by Doppler Ultrasound
Timepoint [1] 5543 0
T = 5, 10, 15, 20, 25 and 30 min
Secondary outcome [2] 5544 0
Total popliteal vein volume flow measured by Doppler Ultrasound
Timepoint [2] 5544 0
T = 5, 10, 15, 20, 25 and 30 min

Eligibility
Key inclusion criteria
Generally healthy adult volunteers with no known vascular history considered significant by the investigator; able to give informed consent.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Unable or unwilling to give informed consent; vascular history considered significant by the investigator; unable to comply with the study requirements; Under 18 years in age.

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)
After informed consent has been obtained subjects will undergo Doppler ultrasound scanning after lying, and sitting for 5 min (sitting with their legs at 2 different angles) in each of the test chairs. The order subjects sit in each of the test seats is determined by random allocation using a computer generated randomisation schedule. The randomisation schedule is generated as a list and is provided to the researcher conducting the subject visits in advance of the trial starting. As the 2 chairs being tested differ in appearance it is not possible to blind the trial hence allocation is not concealed; but the trial design is a crossover so that each subject acts as their own controls thereby reducing allocation bias.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computer program will be used to generate random number sequences.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Pharmacodynamics
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
10/11/2007
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
12
Accrual to date
Final
Recruitment outside Australia
Country [1] 597 0
New Zealand
State/province [1] 597 0

Funding & Sponsors
Funding source category [1] 2852 0
Commercial sector/Industry
Name [1] 2852 0
ErgoCentric Seating Systems
Country [1] 2852 0
Canada
Primary sponsor type
Commercial sector/Industry
Name
ErgoCentric Seating Systems
Address
5616 McAdam Road
Mississauga
Ontario
L4Z1P1
Country
Canada
Secondary sponsor category [1] 2570 0
None
Name [1] 2570 0
Address [1] 2570 0
Country [1] 2570 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 4797 0
Central Regional Ethics Committee
Ethics committee address [1] 4797 0
PO Box 5013
Wellington
Ethics committee country [1] 4797 0
New Zealand
Date submitted for ethics approval [1] 4797 0
27/07/2007
Approval date [1] 4797 0
26/09/2007
Ethics approval number [1] 4797 0
CEN/07/08/062

Summary
Brief summary
The aim of this study is to assess the effects of sitting compared with lying on lower limb venous blood flow and to assess whether the ErgoCentric seat results in a lesser reduction in lower limb venous blood flow than the Herman Miller Aeron chair (an office seat available internationally).
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 28028 0
Address 28028 0
Country 28028 0
Phone 28028 0
Fax 28028 0
Email 28028 0
Contact person for public queries
Name 11185 0
Tanya Baker
Address 11185 0
Medical Research Institute of New Zealand
PO Box 10055
Wellington
Country 11185 0
New Zealand
Phone 11185 0
+64 4 472 9636
Fax 11185 0
+64 4 472 9224
Email 11185 0
[email protected]
Contact person for scientific queries
Name 2113 0
Professor Richard Beasley
Address 2113 0
Medical Research Institute of New Zealand
PO Box 10055
Wellington
Country 2113 0
New Zealand
Phone 2113 0
+64 4 472 9199
Fax 2113 0
+64 4 472 9224
Email 2113 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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

Documents added automatically
No additional documents have been identified.