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Trial registered on ANZCTR


Registration number
ACTRN12616000079448
Ethics application status
Approved
Date submitted
19/01/2016
Date registered
25/01/2016
Date last updated
25/01/2016
Type of registration
Retrospectively registered

Titles & IDs
Public title
Efficacy of a workplace osteoporosis prevention intervention: a cluster randomised trial
Scientific title
Efficacy of a workplace osteoporosis prevention intervention: a cluster randomised trial
Secondary ID [1] 288344 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Osteoporosis; musculoskeletal condition 297332 0
Condition category
Condition code
Musculoskeletal 297577 297577 0 0
Osteoporosis
Public Health 297529 297529 0 0
Health service research

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention methodologies:
Subjects from workplaces assigned to the intervention group received three intensive workshops targeting behaviour change over a period of 6 weeks. The intervention design had a strong focus on behavioural strategies and was participatory in nature. Bandura’s Self–Efficacy Model was used to guide the workshop design for the intervention group.
The workshop design focused on individual goal setting and on building skill sets to attain individual goals. The design avoided presentation style communication and focused on behavioural strategies such as participatory skill building through hands-on activities, goal setting exercises, peer support and problem solving discussions. Attention was placed on helping participants identify individual barriers and build their capacity to overcome them. The intervention also addressed diet and physical activity as different entities that required different behavioural strategies. Though guided by the same principles, the workshops for diet and physically activity were unique in the nature and design of their activities.

Intervention strategy development for calcium intake:
Our study reviewed the content of interventions that reported positive outcomes for dietary calcium intake. The intervention workshops, run by a dietician, included participatory activities such as food preparation and tasting, nutrition label reading exercises, group discussions with exchange of ideas. Emphasis was placed on using specific examples relevant to the participants' lifestyles and tastes as well incorporating local food sources into activities.
In addition, we incorporated quantitative and qualitative dietary information collected at baseline to help tailor intervention strategies. The dietary records were inspected to identify the common food sources of calcium amongst the study population, as well as their consumption patterns and volumes. This information was also be used to tailor strategies that were relevant to individual participants.
The workshop also addressed common barriers to consuming calcium rich foods, identified in previous research include the perception that these foods are higher in price, are mainly dairy products and are high in fat. Taste aversion, mainly to dairy, has also been highlighted as a barrier. These issues were addressed individually in different components of the workshop. Food tasting was a very effective strategy to expose subjects to a wide range of foods that can provide a substantial calcium boost. The ability to correctly read and interpret nutrition labels was identified as a necessary skill to facilitate selection of calcium rich foods. Practical sessions on reading of food labels were included in the intervention.

Intervention strategy development for physical activity:
Physical activity behaviour can have very different psychosocial mediators from dietary behaviour. In this study, physical activity was regarded as a unique behaviour that required a different set of intervention strategies to that for dietary calcium intake.
The types of physical activity that can affect bone mineral density, risk of osteoporosis and risk of fractures are described as load bearing and resistance training exercises. The intensity of activity is also critical. Evidence indicates that only moderate to vigorous level of load-bearing physical activity can affect bone density in important sites such as the hips, a vulnerable site for osteoporotic fractures.
Evidence indicates behavioural strategies to be superior to cognitive strategies and meta-analyses of physical activity interventions emphasise the importance of behavioural interventions, which include goal setting, self-monitoring, physical activity behaviour feedback, consequences, exercise prescription and cues.
Our study adhered to these recommendations when designing intervention activities. In addition, emphasis was placed on providing opportunities to sample a variety of the targeted physical activities. These included take home activity samplers in many formats, including DVDs.
The first workshop discussed the relationship between load bearing and resistance training exercises on bone cell formation and bone modelling. This served to communicate the key message that specific types of exercise are needed to protect and promote bone health. The third workshop was focused entirely on helping participants identify their barriers to increasing their physical activity level and to help them overcome the barriers with individually tailored strategies.
The intervention for physical activity was facilitated by a physiotherapist. The aims of the intervention were to encourage participants to problem solve and develop strategies to help them increase their moderate to vigorous intensity load-bearing physical activity by 60 minutes per week. Each participant would record their weekday and weekend routine to be shared within a group. In the design of the intervention, peer support was identified as an important mediator for behaviour change and hence the emphasis on group work. This allowed participants to identify common barriers to change, develop strategies together and support one another through problem solving on common issues. Workshop participants shared a common work environment and would be able to develop workplace based strategies based on shared experience. This facilitated discussion as participants shared many ideas that were based on common experience, such as workplace stair access for opportunistic physical activity, discussion of suitable walking routes around the workplaces and sharing of information about exercise facilities near the work premises.
Unique strategies were developed for this study to facilitate the attainment of the physical activity goal with minimal disruption to the participants’ routine. One important strategy was to introduce short bouts of exercise breaks (5–10 minutes) during television viewing time or work time, which many participants would regard as achievable and sustainable. Participants would devise different types of 5–10 minute exercise routines that required minimal room and could be carried out easily at home or at the workstation. Resources, such as an exercise CD and a 10-minute exercise poster with instructions and illustrations would be provided to each participant. The latter was developed specifically for this intervention.

The duration of each workshop is 90 minutes/1.5 hours. The frist workshop educated about bone health and osteopososis, risk of osteoporosis and lifestyle prevention measures. The first workshop also included education on how calcium intake and physical activity can help imact on osteoporosis.. The session intorduced participants to types of dietary calcium sources and the types of physical activity that is beneficial for bone health..

The second workshop focused solely calcium intake and the third workshop focused solely on physical activity..

Records of the attendance were taken at the workshops.
Intervention code [1] 293651 0
Behaviour
Comparator / control treatment
Control treatment group received education material that included print information about osteoporosis, risks and consequences of the disease condition, lifestyle prevention strategies, including national recommendations for calcium intake and physical activity. The print resources also include information about calcium rich foods and provide examples of a calcium rich diet. The resource pack also includes an exercise DVD that provided examples of the types of physical activity that is beneficial for bone health. This was the minimum care standard.

Ethical considerations for control group:
Educational resource distribution was a strategy that was already in place for promoting bone health awareness in many Singaporean workplaces. The resources on osteoporosis
prevention (described above) were widely distributed through various platforms such as community events, workplaces and health facilities. It would not be appropriate for workplaces in the control arm to receive less than an existing intervention, hence the standard care control.

The purpose of the study was to investigate if a more targeted and structured intervention with organisational support is more efficacious than existing practice. It was
important to maintain the existing practices/strategy for the control group for the comparison to be purposeful and to determine the extent to which current practice can be improved upon. These were the key ethical considerations for the study design.
Control group
Active

Outcomes
Primary outcome [1] 297086 0
Calcium intake in milligrams per day.

Calcium intake was measured using a three-day diet record. This method involved each participant keeping a detailed written record of the foods and beverages consumed
over three days. Three day recording was selected as recording periods of more than three or four days were reported to be unreliable due to respondent fatigue. Specific emphasis was put on the correct description of portion sizes so that an accurate estimate of calcium
content could be derived.
An appointment was scheduled to meet each participant individually to provide specific instructions for completion of the three-day diet record. The three days would include
two representative weekdays and one representative weekend day. Completed dietary records were collected and sent to a qualified nutritionist for analysis to establish the calcium content. The nutritionist was blinded to the treatment arms and the identities of the workplaces and participants.
Timepoint [1] 297086 0
Baseline, four weeks post intervention and six months post intervention.
Primary outcome [2] 297089 0
Load-bearing moderate to vigorous physical activity in minutes per week.

Physical activity was measured using the EPIC Norfolk
Physical Activity Questionnaire 2 (EPAQ-2). The EPAQ-2 was designed to measure the different sub-dimensions of physical activity in the Norfolk cohort of the European
Prospective Investigation into Cancer (EPIC-Norfolk) in 1999. It is a self-reported questionnaire on disaggregated physical activity enabling the data be re-aggregated
to the dimension of physical activity of interest, for example load-bearing activity of relevance to osteoporosis prevention. The EPAQ-2 has been validated against fourday
heart rate measurement and was concluded to have the validity and repeatability/reliability to be used in a large-scale epidemiological study. The questionnaire consists of three sections: activity at home, work and recreation.
Permission was obtained from Wareham and Jakes to adapt and use the instrument for this study.
The content of the EPAQ-2 was assessed for cultural appropriateness by a panel that included experts from inside and outside the Health Promotion Board (Singapore).
Minor modifications were made to the list of recreation activities. Activities that were not relevant to local context, such as “digging, shovelling or chopping wood” were removed,
and replaced with common local activities not included in the version developed for use in Europe, such as Tai Chi. Seventeen women at a workplace (not involved in the study) assessed the ease of reading using the Flesch reading ease score. They also provided feedback on the ease of understanding and the ease of completing the
modified EPAQ-2. Minor changes were made to the language of instructions on the questionnaires to further increase ease of understanding. Prompts were added in sections where extra information needed to be provided, for example duration of each session recreation activity, to facilitate thorough completion of the questionnaire.
A copy of the EPAQ-2 was sent to each participant through the workplace coordinator. The participants completed the questionnaire independently and submitted it to the investigator at each data collection point. The investigator checked that the EPAQ-2 was completed according to instructions.
Timepoint [2] 297089 0
Baseline, four weeks post intervention and six months post intervention
Secondary outcome [1] 320004 0
Self-efficacy scores for calcium intake

Self-efficacy was measured using the osteoporosis self-efficacy scale developed and evaluated by Horan et al. in 1998. Written permission was sought from the authors
to use the instrument.
The content of the questionnaire was assessed for appropriateness to local context by a panel that included experts internal and external to the Health Promotion Board (Singapore). It was also validated for internal consistency and test-retest repeatability through an evaluation process involving 17 women at a workplace (not involved
in the study). The original content was found to be relevant to the local context and the questionnaire to have appropriate reliability for use in this study.
Each subject was sent a physical copy of the questionnaire through the workplace coordinator. The completed questionnaires were returned to the workplace coordinator
who collated the submissions and dispatched them to the investigator.
Timepoint [1] 320004 0
Baseline, four weeks post intervention and six months post intervention.
Secondary outcome [2] 320006 0
Self-efficacy scores for exercise

Self-efficacy was measured using the osteoporosis self-efficacy scale developed and evaluated by Horan et al. in 1998. Written permission was sought from the authors
to use the instrument.
The content of the questionnaire was assessed for appropriateness to local context by a panel that included experts internal and external to the Health Promotion Board (Singapore). It was also validated for internal consistency and test-retest repeatability through an evaluation process involving 17 women at a workplace (not involved
in the study). The original content was found to be relevant to the local context and the questionnaire to have appropriate reliability for use in this study.
Each subject was sent a physical copy of the questionnaire through the workplace coordinator. The completed questionnaires were returned to the workplace coordinator
who collated the submissions and dispatched them to the investigator.
Timepoint [2] 320006 0
Baseline, four weeks post intervention and six months post intervention.

Eligibility
Key inclusion criteria
Workplace (cluster) inclusion criteria
* Workplaces in sectors or industries that were primarily office based and sedentary in nature, such as government administration departments and finance;
*Workplaces that were able to recruit at least 30 female employees engaged in desk-based jobs (sitting for at least 50% of working hours); and
*Agreement to permit up to 10 hours of paid work time during the course of the study (12 months) for the recruited employees to participate in pre-post data collection and intervention activities.

Eligibility for recruitment of employees within selected workplaces:
*Being female;
*Age 25–49 years of age; and
*Being in a sedentary job (at least 50% of work hours seated)
Minimum age
25 Years
Maximum age
49 Years
Sex
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Exclusion criteria were:
*Being pregnant or lactating;
*Diagnosed osteoporosis;
*Diagnosed kidney problems; and
*Participation in another health program that addressed diet and/or physical activity.

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)
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 receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Cluster randomisation
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Sample size calculation:

Sample size calculations took into consideration the cluster randomisation design by incorporating the design effect into the calculation. The design effect was calculated based on a cluster size of 20 and the intracluster correlation coefficient (ICC) using the formula: Design Effect = 1 + (within cluster sample size -1) x ICC. In the absence of ICCs for the outcome measures, available population standard deviations were used to calculate the variances and the ICC using the formula: ICC = variance between cluster/(variance between cluster + variance within cluster). In this study, there were two primary outcome measures, calcium intake and physical activity. Sample size calculations were carried out for both measures. Calculations were based on a = 0.05 and beta = 0.1. The ICCs used for calculation of sample size was 0.5 for calcium intake and 0.05 for physical activity. The study deliberately planned to over recruit within clusters to factor in a 30% attrition rate. The number of clusters required was different for each outcome measure, so the study was based on the highest number of clusters required, which was that for calcium intake (14.7). This was rounded up to 16 to ensure equal cluster numbers in both arms of this study. This study has 90% power to detect 355 milligrams increase in calcium intake and 85 minutes increase in moderate to vigorous intensity physical activity with 16 clusters of 20 participants per cluster.

Data analysis:
Statiscal analysis in full adhererence to the CONSORT guidelines for cluster randomised trials..

This study used the two-stage adjusted analysis based on cluster summaries developed by Hayes and Moulten "Cluster Randomised Trials" (2009, pp182-184). In stage one, SPSS linear regression was run to generate an unstandardised residual for each subject (the difference between the observed value and the fitted value from the model for each individualparticipant).. Baseline values, personal income, education and religion for each subject were controlled for in the linear regression model. This step incorporated repeated measures into the analysis and generates the covariate-adjusted residuals for each individual.
Cluster summaries for the covariate-adjusted residuals were then generated using SPSS descriptive statistics.for stage two of the analysis
These summaries were for stage two of the analysis, which was the cluster level analysis. The cluster means of the residuals were then compared in a cluster level analysis
using a t-test,

As described above, the study plan was to over recruit within cluster by 30% to account for the attrition rate.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
20/06/2005
Date of last participant enrolment
Anticipated
Actual
26/08/2005
Date of last data collection
Anticipated
Actual
Sample size
Target
416
Accrual to date
Final
585
Recruitment outside Australia
Country [1] 7537 0
Singapore
State/province [1] 7537 0

Funding & Sponsors
Funding source category [1] 292708 0
Government body
Name [1] 292708 0
Health Promotion Board (Singapore)
Country [1] 292708 0
Singapore
Primary sponsor type
Individual
Name
Ai May Tan
Address
University of Melbourne
School of Population Health
Level 4, 207 Bouverie Street
The University of Melbourne
Victoria, 3010, Australia
Country
Australia
Secondary sponsor category [1] 291470 0
None
Name [1] 291470 0
None
Address [1] 291470 0
NA
Country [1] 291470 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294195 0
University of Melbourne, School of Population Health Human Ethics Advisory Group (SPH HEAG)
Ethics committee address [1] 294195 0
Ethics committee country [1] 294195 0
Australia
Date submitted for ethics approval [1] 294195 0
20/06/2011
Approval date [1] 294195 0
12/08/2011
Ethics approval number [1] 294195 0
1136880
Ethics committee name [2] 294194 0
Health Promotion Board (Singapore)
Ethics committee address [2] 294194 0
Ethics committee country [2] 294194 0
Singapore
Date submitted for ethics approval [2] 294194 0
10/03/2005
Approval date [2] 294194 0
25/05/2005
Ethics approval number [2] 294194 0
001/2005

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 62826 0
Ms Ai May Tan
Address 62826 0
Level 4, 207 Bouverie Street
The University of Melbourne
Victoria, 3010, Australia
Country 62826 0
Australia
Phone 62826 0
+61-434005040
Fax 62826 0
Email 62826 0
amtan@student.unimelb.edu.au
Contact person for public queries
Name 62827 0
Ai May Tan
Address 62827 0
Level 4, 207 Bouverie Street
The University of Melbourne
Victoria, 3010, Australia
Country 62827 0
Australia
Phone 62827 0
+61-434005040
Fax 62827 0
Email 62827 0
amtan@student.unimelb.edu.au
Contact person for scientific queries
Name 62828 0
Ai May Tan
Address 62828 0
Level 4, 207 Bouverie Street
The University of Melbourne
Victoria, 3010, Australia
Country 62828 0
Australia
Phone 62828 0
+61-434005040
Fax 62828 0
Email 62828 0
amtan@student.unimelb.edu.au

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