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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Reducing sedentary behaviour in office workers
Scientific title
Education and adjustable sit-stand workstations to reduce sedentary behaviour at work in office workers. A randomised controlled trial.
Secondary ID [1] 282226 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Sedentary behaviour, in particular prolonged sitting in office workers 288740 0
Condition category
Condition code
Metabolic and Endocrine 289096 289096 0 0
Normal metabolism and endocrine development and function
Musculoskeletal 289097 289097 0 0
Other muscular and skeletal disorders
Public Health 289135 289135 0 0
Health promotion/education

Study type
Description of intervention(s) / exposure
Education intervention: Participants in this group will receive an advice/education package that has been designed to improve their knowledge and understanding about the detrimental effects of prolonged sitting and to change their behaviour in relation to sitting habits. The education package includes a single twenty-minute multimedia presentation. Participants in this group will set personal physical activity goals and monitor their own daily step counts for one month.

Sit-stand desk intervention: Participants in this group will receive the same education package as the education intervention group. Participants in this group will be also be provided with a Workfit (Registered Trademark) adjustable sit-stand workstation for a period of four weeks.
Participants will receive a single five minute one-on-one demonstration in the use and adjustment of the workstation with. Participants will set individual goals for the time that they will spend working in a standing position. Participants will be free to adjust the work station at their own discretion. Participants will be given the general advice to alternate regularly between work in a sitting and standing position and discouraged from trying to only work in a standing position.
Intervention code [1] 286836 0
Intervention code [2] 286876 0
Intervention code [3] 286877 0
Comparator / control treatment
No intervention: Participants in this group will receive no information or advice about postural change and no modification to their office desk set up. Participants in the control group will be offered the education intervention once they have completed final data collection and they have been discharged from their involvement in the study.
Control group

Primary outcome [1] 289206 0
Average sitting time (hours) during a work day. Sitting time will be measured using an acelerometer over a seven day period
Timepoint [1] 289206 0
Four weeks
Secondary outcome [1] 302029 0
Average number of breaks from sitting per day. The number of breaks from sitting will be measured using an acelerometer over a period of seven days
Timepoint [1] 302029 0
Four weeks
Secondary outcome [2] 302030 0
Self reported sitting time will be established using the Occupational Sitting and Physical Activity Questionnaire and the Workforce Sitting Questionnaire (Chau et. al 2012).
Timepoint [2] 302030 0
Four Weeks
Secondary outcome [3] 302031 0
Seven-day prevalence of musculoskeletal symptoms will be recorded using the Nordic Musculoskeletal Questionnaire (Kuorinka et. al. 1987).
Timepoint [3] 302031 0
Four weeks
Secondary outcome [4] 302032 0
Self reported work ability will be measured by the Work Ability Index (Tuomi 1998)
Timepoint [4] 302032 0
Four weeks

Key inclusion criteria
Participants will be included in the study if they are currently employed in a full time academic or administrative role at The University of Sydney. Particiapnats must work in a role that involves greater then 15 hours per week or greater than 4 hours per day computer-based work.

Minimum age
No limit
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Participants will be excluded if they have; planned leave during the study period, any self-reported chronic illness, any self-reported musculoskeletal injury or condition or if they have a current worker’s compensation claim.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will be recruited by advertisement from academic and administrative staff at The University of Sydney. Posters will be placed in staff tearooms and common areas, inviting staff to participate in “The Healthier Office Study”. The advertisements will contain the general information informing participants that we are testing simple occupational health interventions and that participants will be provided with an ergonomic device or advice about improving healthy work practices. The advertisements will not contain specific detail about the interventions in order to keep the participants blinded to the interventions that they do not receive.

A researcher who is blinded to subject allocation will collect baseline and outcome data. Baseline data will be collected from participants at the initial assessment to obtain a profile of the participant’s demographic, work and general health characteristics.

A researcher who is not involved in participant recruitment or data collection will produce a randomly generated sequence for allocating participants to one of the three groups. This will be done prior to commencement of the trial. This researcher will prepare consecutively numbered sealed opaque envelopes that contain the group allocation for each individual participant. The envelope for each participant will be opened after the participant has enrolled in the study and after baseline data is collected. The randomisation sequence will contain equal numbers of subjects in each group but will be otherwise unrestricted.

A researcher who is blinded to the participant allocation will perform data entry and analysis.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Data collection will take place away from the participants’ office and data collectors will be instructed not to enter the office areas of participants. This will ensure blinding of the data collectors to allocation of participants to the sit-stand desk intervention group. The office set-up in the workplace setting for this trial is predominantly private, single occupier offices with few work centres using open plan office design. This feature of the study setting will assist with maintaining blinding of participants and data collectors.

Participants in the control group will be kept naïve as to the main aim of the study i.e. reduction of unhealthy sitting behaviours. This is because it is believed by the research team that participants being aware that the primary outcome is to reduce sitting behaviour, might actually change this behaviour. It is therefore also necessary that participants be blinded as to the intervention groups to which they are not allocated. Knowledge of the other intervention being tested, both being clearly interventions designed to reduce sitting behaviour might also impact on the sitting behaviour of participants. Participants will therefore be informed that they are participating in a trial of general workplace health interventions and remain blinded to the other intervention groups.

Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The primary analysis will be by intention-to-treat. Repeated measures of ANOVA will be used to determine within group and between group differences in the recorded outcome measures.

We did not conduct a formal power analysis to determine sample size; this is because the threshold for defining harmful levels of sitting is unknown. The proposed sample size of this study is similar to previous pilot studies of workplace sitting and sedentary time. Our sample of 60 participants (three groups of 20 participants) should be sufficient for assessing the direction of intervention effects while taking into account possible missing data and participation attrition.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 6642 0
2141 - Lidcombe

Funding & Sponsors
Funding source category [1] 286984 0
Name [1] 286984 0
Heart Foundation of Australia
Address [1] 286984 0
Level 3, 80 William Street Sydney NSW 2011
Country [1] 286984 0
Primary sponsor type
Dr Andrew Leaver
Faculty of Health Sciences The University of Sydney East St Lidcombe NSW 2141
Secondary sponsor category [1] 285772 0
Name [1] 285772 0
Dr Martin Mackey
Address [1] 285772 0
Faculty of Health Sciences The University of Sydney East St Lidcombe NSW 2141
Country [1] 285772 0

Ethics approval
Ethics application status
Ethics committee name [1] 289033 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 289033 0
Level 6, Jane Foss Russell Building - G02
The University of Sydney
Ethics committee country [1] 289033 0
Date submitted for ethics approval [1] 289033 0
Approval date [1] 289033 0
Ethics approval number [1] 289033 0

Brief summary
Prolonged sitting at work has been identified as a significant occupational health concern, and there is a need for effective interventions that reduce potentially unhealthy sitting behaviour in particular occupational groups such as office workers. This study will compare the effectiveness of two simple occupational health interventions in reducing these potentially unhealthy sitting behaviour in office workers. This study will determine whether providing office workers with an adjustable sit-stand desk and individually targeted education is more effective in decreasing sitting behaviours than education alone or providing no intervention.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 38898 0
Dr Martin Mackey
Address 38898 0
Faculty of Health Sciences, The University of Sydney
PO Box 170 Lidcombe NSW 1825
Country 38898 0
Phone 38898 0
+61 2 9351 9374
Fax 38898 0
Email 38898 0
Contact person for public queries
Name 38899 0
Dr Andrew Leaver
Address 38899 0
Faculty of Health Sciences, The University of Sydney
PO Box 170 Lidcombe NSW 1825
Country 38899 0
Phone 38899 0
+61 2 9351 9545
Fax 38899 0
Email 38899 0
Contact person for scientific queries
Name 38900 0
Dr Martin Mackey
Address 38900 0
Faculty of Health Sciences, The University of Sydney
PO Box 170 Lidcombe NSW 1825
Country 38900 0
Phone 38900 0
+61 2 9351 9374
Fax 38900 0
Email 38900 0

No information has been provided regarding IPD availability
Summary results
No Results