Healthy together Victoria and childhood obesity-a methodology for measuring changes in childhood obesity in response to a community-based, whole of system cluster randomized control trial

Building a systems-thinking community workforce to scale action on determinants of health in New Zealand

This article describes findings from the evaluation of Healthy Families NZ (HFNZ), an equity-driven, place-based community health initiative. Implemented in nine diverse communities across New Zealand, HFNZ aims to strengthen the systems that can improve health and well-being. Findings highlight local needs and priorities including the social mechanisms important for reorienting health and policy systems towards place-based communities. Lessons encompass the importance of local lived experience in putting evidence into practice; the strength of acting with systems in mind; the need for relational, learning, intentional, and well-resourced community organisation; examples of how to foster place-based 'community-up' leadership; and how to enable responsiveness between communities and local and national policy systems. A reconceptualisation of scaling in the context of complexity and systems change is offered, which recognises that relationships and agency are key to making progress on the determinants of health.

Healthy together Victoria and childhood obesity study: effects of a large scale, community-based cluster randomised trial of a systems thinking approach for the prevention of childhood obesity among secondary school students 2014-2016

BACKGROUND

Healthy Together Victoria (HTV) was a Victorian Government initiative that sought to reduce the prevalence of overweight and obesity through targeting chronic disease risk factors including physical activity, poor diet quality, smoking, and harmful alcohol use. The intervention involved a boosted workforce of > 170 local-level staff in 12 communities; employed to deliver system activation around health and wellbeing for individuals, families and communities. A cluster randomised trial (CRT) of a systems thinking approach to obesity prevention was embedded within HTV. We present the two-year changes in overweight and obesity and associated behaviours among secondary school students across Victoria, Australia.

METHODS

Twenty-three geographically bounded areas were randomised to intervention (12 communities) or comparison (11 communities). Randomly selected secondary schools within each community were invited to participate in the trial in 2014 and 2016. Students in Grade 8 (aged approximately 13-15 years) and Grade 10 (aged approximately 15-16 years) at participating schools were recruited using an opt-out approach across July-September 2014 and 2016. Primary outcomes were body mass index (BMI) and waist circumference. Secondary outcomes were physical activity, sedentary behaviour, diet quality, health-related quality of life, and depressive symptoms. Linear mixed models were fit to estimate the intervention effect adjusting for child/school characteristics.

RESULTS

There were 4242 intervention children and 2999 control children in the final analysis. For boys, the two-year change showed improvement in intervention versus control for waist circumference (difference in change: - 2.5 cm; 95% confidence interval [CI]: - 4.6, - 0.5) and consumption of sugar-sweetened beverages per day (< 1 serve: 8.5 percentage points; 95% CI: 0.6, 16.5). For girls, there were no statistically significant differences between conditions.

CONCLUSIONS

HTV seemed to produce favourable changes in waist circumference and sugar-sweetened beverage consumption for boys, however, no effect on BMI was observed. Although the HTV intervention was cut short, and the period between data collection points was relatively short, the changes observed in HTV contribute to the growing evidence of whole-of-community interventions targeting childhood obesity.

TRIAL REGISTRATION

This trial is unregistered. The intervention itself was a policy setting delivered by government and our role was the collection of data to evaluate the effect of this natural experiment. That is, this study was not a trial from the classical point of view and we were not responsible for the intervention.

How healthy and affordable are foods and beverages sold in school canteens? A cross-sectional study comparing menus from Victorian primary schools

OBJECTIVE

Government policy guidance in Victoria, Australia, encourages schools to provide affordable, healthy foods in canteens. This study analysed the healthiness and price of items available in canteens in Victorian primary schools and associations with school characteristics.

DESIGN

Dietitians classified menu items (main, snack and beverage) using the red, amber and green traffic light system defined in the Victorian government's School Canteens and Other School Food Services Policy. This system also included a black category for confectionary and high sugar content soft drinks which should not be supplied. Descriptive statistics and regressions were used to analyse differences in the healthiness and price of main meals, snacks and beverages offered, according to school remoteness, sector (government and Catholic/independent) size, and socio-economic position.

SETTING

State of Victoria, Australia.

PARTICIPANTS

A convenience sample of canteen menus drawn from three previous obesity prevention studies in forty-eight primary schools between 2016 and 2019.

RESULTS

On average, school canteen menus were 21 % 'green' (most healthy - everyday), 53 % 'amber' (select carefully), 25 % 'red' (occasional) and 2 % 'black' (banned) items, demonstrating low adherence with government guidelines. 'Black' items were more common in schools in regional population centres. 'Red' main meal items were cheaper than 'green'% (mean difference -$0·48 (95 % CI -0·85, -0·10)) and 'amber' -$0·91 (-1·27, -0·57)) main meal items. In about 50 % of schools, the mean price of 'red' main meal, beverages and snack items were cheaper than 'green' items, or no 'green' alternative items were offered.

CONCLUSION

In this sample of Victorian canteen menus, there was no evidence of associations of healthiness and pricing by school characteristics except for regional centres having the highest proportion of 'black' (banned) items compared with all other remoteness categories examined. There was low adherence with state canteen menu guidelines. Many schools offered a high proportion of 'red' food options and 'black' (banned) options, particularly in regional centres. Unhealthier options were cheaper than healthy options. More needs to be done to bring Victorian primary school canteen menus in line with guidelines.

Combining systems thinking approaches and implementation science constructs within community-based prevention: a systematic review

BACKGROUND

Systems science offers methods for designing population health interventions while implementation science provides specific guidance for successful implementation. Integrating systems and implementation science may strengthen implementation and enhance and sustain systemic change to achieve system-level outcomes. Little is known about the extent to which these two approaches have been integrated to date. This review aimed to identify and synthesise the peer-reviewed literature that has reported the combined use of systems thinking approaches and implementation science constructs (within the same study), to deliver population health interventions.

METHODS

A systematic literature search of peer-reviewed original research was conducted across six databases from 2009 to 2021. Journal manuscripts were included if they: (1) reported on a population health study conducted in a community, (2) reported the use of a systems method in the design of the intervention, and (3) used an implementation science theory, framework or model in the delivery of the intervention. Data extracted related to the specific systems methods and definitions and implementation science constructs used. The Mixed Methods Appraisal Tool (MMAT) was used to assess study quality.

RESULTS

Of the 9086 manuscripts returned, 320 manuscripts were included for full-text review. Of these, 17 manuscripts that reported on 14 studies were included in the final extraction. The most frequently reported systems methods were a 'whole of community systems approach' (n = 4/14) and 'community-based system dynamics' (n = 2/14). Nineteen different implementation science theories, frameworks and models were used for intervention delivery, with RE-AIM being the only framework used in more than one study.

CONCLUSION

There are few published peer-reviewed studies using systems thinking and implementation science for designing and delivering population health interventions. An exploration of synergies is worthwhile to operationalise alignment and improve implementation of systems thinking approaches. Review protocol registration PROSPERO CRD42021250419.

Building capacity for the use of systems science to support local government public health planning: a case study of the VicHealth Local Government Partnership in Victoria, Australia

OBJECTIVE

To present an approach to build capacity for the use of systems science to support local communities in municipal public health and well-being planning.

DESIGN

Case study.

SETTING

Local government authorities participating in the VicHealth Local Government Partnership in Victoria, Australia.

PARTICIPANTS

Local government staff members were trained in community-based system dynamics (CBSD), and group model building (GMB) techniques to mobilise local community efforts. The trained local government facilitation teams then delivered GMB workshops to community stakeholder groups from 13 local government areas (LGA)s.

MAIN OUTCOMES

Training in CBSD was conducted with council facilitation teams in 13 LGAs, followed by the local delivery of GMB workshops 1-3 to community stakeholders. Causal loop diagrams (CLD) representing localised drivers of mental well-being, healthy eating, active living or general health and well-being of children and young people were developed by community stakeholders. Locally tailored action ideas were generated such as well-being classes in school, faster active transport and access to free and low-cost sporting programmes RESULTS: Overall, 111 local government staff participated in CBSD training. Thirteen CLDs were developed, with the stakeholders that included children, young people and community members, who had participated in the GMB workshops across all 13 council sites. Workshop 3 had the highest total number of participants (n=301), followed by workshop 1 (n=287) and workshop 2 (n=171).

CONCLUSIONS

Local facilitation of the CBSD process has developed community informed and locally relevant CLDs that will be used to lead local action to improve the well-being of children and young people. Training employees in CBSD is one approach to increase systems thinking capacity within local government.

Reflexive Evidence and Systems interventions to Prevention Obesity and Non-communicable Disease (RESPOND): protocol and baseline outcomes for a stepped-wedge cluster-randomised prevention trial

INTRODUCTION

Systems science methodologies have been used in attempts to address the complex and dynamic causes of childhood obesity with varied results. This paper presents a protocol for the Reflexive Evidence and Systems interventions to Prevention Obesity and Non-communicable Disease (RESPOND) trial. RESPOND represents a significant advance on previous approaches by identifying and operationalising a clear systems methodology and building skills and knowledge in the design and implementation of this approach among community stakeholders.

METHODS AND ANALYSIS

RESPOND is a 4-year cluster-randomised stepped-wedge trial in 10 local government areas in Victoria, Australia. The intervention comprises four stages: catalyse and set up, monitoring, community engagement and implementation. The trial will be evaluated for individuals, community settings and context, cost-effectiveness, and systems and implementation processes. Individual-level data including weight status, diet and activity behaviours will be collected every 2 years from school children in grades 2, 4 and 6 using an opt-out consent process. Community-level data will include knowledge and engagement, collaboration networks, economic costs and shifts in mental models aligned with systems training. Baseline prevalence data were collected between March and June 2019 among >3700 children from 91 primary schools.

ETHICS AND DISSEMINATION

Ethics approval: Deakin University Human Research Ethics Committee (HREC 2018-381) or Deakin University's Faculty of Health Ethics Advisory Committee (HEAG-H_2019-1; HEAG-H 37_2019; HEAG-H 173_2018; HEAG-H 12_2019); Victorian Government Department of Education and Training (2019_003943); Catholic Archdiocese of Melbourne (Catholic Education Melbourne, 2019-0872) and Diocese of Sandhurst (24 May 2019). The results of RESPOND, including primary and secondary outcomes, and emerging studies developed throughout the intervention, will be published in the academic literature, presented at national and international conferences, community newsletters, newspapers, infographics and relevant social media.

TRIAL REGISTRATION NUMBER

ACTRN12618001986268p.

A system dynamic perspective of stop-start prevention interventions in Australia

Time-limited prevention initiatives are frequently used to address complex and persisting public health issues, such as non-communicable diseases. This often creates issues in terms of achieving sustainable change. In this study, we use a system dynamic perspective to explore the effects of stop-start funding over system behaviour in two community-based initiatives designed to prevent chronic diseases and obesity. We conducted a qualitative exploratory study using complexity theory as an analytical lens of two Healthy Together Communities (HTCs) initiatives in Victoria, Australia. Data were generated from 20 semi-structured interviews with health promotion practitioners and managers, from community health and local government organizations. Template analysis based on properties of complex systems informed the inductive identification of system behaviour narratives across the stop-start life-course of HTCs. A central narrative of system behaviour emerged around relationships. Within it, we identified pre-existing contextual conditions and intervention design elements that influenced non-linearity of system self-organization and adaptation, and emergence of outcomes. Examples include cynicism, personal relationships and trust, and history of collaboration. Feedback loops operated between HTCs and these conditions, in a way that could influence long-term system behaviour. Taking a dynamic life-course view of system behaviour helps understand the pre-existing contextual factors, design and implementation influences, and feedback loops which shape the long-term legacy of short-lived interventions aimed at solving complex issues. In turn, greater awareness of such interactions can inform better design and implementation of community-based interventions.

Together stronger: boundary work within an Australian systems-based prevention initiative

Complexity and systems science are increasingly used to devise interventions to address health and social problems. Boundaries are important in systems thinking, as they bring attention to the power dynamics that guide decision-making around the framing of a situation, and how it is subsequently tackled. Using complexity theory as an analytical frame, this qualitative exploratory study examined boundary interactions between local government and community health organizations during the operationalization of a systems-based initiative to prevent obesity and chronic diseases (Healthy Together Communities-HTCs) in Victoria, Australia. Across two HTC sites, data was generated through semi-structured interviews with 20 key informants, in mid-2015. Template analysis based on properties of complex systems was applied to the data. The dynamics of boundary work are explored using three case illustrations: alignment, boundary spanning and boundary permeability. Alignment was both a process and an outcome of boundary work, and occurred at strategic, operational and individual levels. Boundary spanning was an important mechanism to develop a unified collaborative approach, and ensure that mainstream initiatives reached disadvantaged groups. Finally, some boundaries exhibited different levels of permeability for local government and community health organizations. This influenced how each organization could contribute to HTC interventions in unique, yet complementary ways. The study of boundary work offers potential for understanding the mechanisms that contribute to the nonlinear behaviour of complex systems. The complementarity of partnering organizations, and boundary dynamics should be considered when designing and operationalizing multilevel, complex systems-informed prevention initiatives.

Building a Prevention System: Infrastructure to Strengthen Health Promotion Outcomes

Prevention systems improve the performance of health promotion interventions. This research describes the establishment of the Australian state government initiative, Healthy Together Victoria's (HTV) macro infrastructure for the delivery of large-scale prevention interventions.

METHODS

This paper reports on findings of 31 semi-structured interviews about participants' understanding of systems thinking and their reflections of the strengths and weaknesses of the HTV prevention system. A chronic disease prevention framework informed the coding that was used to create a causal loop diagram and a core feedback loop to illustrate the results.

RESULTS

Findings highlighted that HTV created a highly connected prevention system that included a sizeable workforce, significant funding and supportive leadership. Operating guidelines, additional professional development and real-time evaluation were significant gaps, which hindered systems practice. For inexperienced systems thinkers, these limitations encouraged them to implement programs, rather than interact with the seemingly ambiguous systems methods.

CONCLUSIONS

HTV was an innovative attempt to strengthen health promotion infrastructure, creating a common language and shared understanding of prevention system requirements. However, the model was inadequate for HTV to achieve population-level reductions in chronic disease as system oversight was missing, as was an intervention delivery focus. Clarity was needed to define the systems practice that HTV was seeking to achieve. Importantly, the HTV prevention system needed to be understood as complex and adaptive, and not prioritized as individual parts.

Understanding the dynamics of obesity prevention policy decision-making using a systems perspective: A case study of Healthy Together Victoria

INTRODUCTION

Despite global recommendations for governments to implement a comprehensive suite of policies to address obesity, policy adoption has been deficient globally. This paper utilised political science theory and systems thinking methods to examine the dynamics underlying decisions regarding obesity prevention policy adoption within the context of the Australian state government initiative, Healthy Together Victoria (HTV) (2011-2016). The aim was to understand key influences on policy processes, and to identify potential opportunities to increase the adoption of recommended policies.

METHODS

Data describing government processes in relation to the adoption of six policy interventions considered as part of HTV were collected using interviews (n = 57), document analyses (n = 568) and field note observations. The data were analysed using multiple political science theories. A systematic method was then used to develop a Causal Loop Diagram (CLD) for each policy intervention. A simplified meta-CLD was generated from synthesis of common elements across each of the six policy interventions.

RESULTS

The dynamics of policy change could be explained using a series of feedback loops. Five interconnected balancing loops served to reduce the propensity for policy change. These pertained to an organisational norm of risk aversion, and the complexity resulting from a whole-of-government policy approach and in-depth stakeholder consultation. However, seven virtuous reinforcing loops helped overcome policy resistance through policy actor capabilities that were improved over time as policy actors gained experience in advocating for change.

CONCLUSION

Policy processes for obesity prevention are complex and resistant to change. In order to increase adoption of recommended policies, several capabilities of policy actors, including policy skills, political astuteness, negotiation skills and consensus building, should be fostered and strengthened. Strategies to facilitate effective and broad-based consultation, both across and external to government, need to be implemented in ways that do not result in substantial delays in the policy process.

Developing a Systems Mindset in Community-Based Prevention

Background. A systems mindset is the ability to see problems in their wider context and in terms of their underlying structure. This research describes how a systems mindset was understood and applied by prevention practitioners in a large-scale community-based initiative that employed a systems thinking approach. Method. This qualitative research included 31 primary semistructured interviews. Deductive thematic analysis was based on Braun and Clarke's analysis framework and was guided by Senge and Scharmer's knowledge-creating system. Results. The practitioners had been introduced to systems theory and were aware of complex problems and the need for equally sophisticated solutions. Their knowledge was not in-depth, although this may be adequate, as a theoretical overview seemed to be sufficient to support practice. A range of tools was available to practitioners to guide their systems mindset; however, none were preferred. Practitioners' awareness of the tools varied, as did their feelings toward them as some found them helpful and others did not. A narrower focus on tools could have benefited those who had not yet grasped systems theory. The use of projects within a systems approach confused some practitioners, yet others saw them as platforms to leverage change from. Implications for practice. With a systems mindset practitioners are able to develop systemic solutions to difficult problems. To do this, they require an overview of complex adaptive systems theory, an applied understanding of systems tools, and an experiential learning opportunity to shift their knowledge into practical know-how.

Weight status and obesity-related dietary behaviours among culturally and linguistically diverse (CALD) children in Victoria, Australia

Background

In developed economies, obesity prevalence is high within children from some culturally and linguistically diverse (CALD) backgrounds. This study aims to identify whether CALD groups in Victoria, Australia, are at increased risk of childhood overweight and obesity, and obesity-related dietary behaviours; compared to their non-CALD counterparts.

Methods

Objective anthropometric and self-report dietary behavioural data were collected from 2407 Grade 4 and 6 primary school children (aged 9–12 years). Children were categorised into CALD and non-CALD cultural groups according to the Australian Standard Classification of Languages. Overweight/obesity was defined according to the World Health Organization growth reference standards. Obesity-related dietary behaviour categories included excess consumption of takeaway foods, energy-dense, nutrient-poor snacks and sugar sweetened beverages. T-tests and chi-square tests were performed to identify differences in weight status and dietary behaviours between CALD and non-CALD children. Logistic regression analyses examined the relationship between CALD background, weight status and dietary behaviours.

Results

Middle-Eastern children had a higher overweight/obesity prevalence (53.0%) than non-CALD children (36.7%; p < 0.001). A higher proportion of Middle-Eastern children had excess consumption of takeaway foods (54.9%), energy-dense, nutrient-poor snacks (36.6%) and sugar sweetened beverages (35.4%) compared to non-CALD children (40.4, 27.0 and 25.0%, respectively; p < 0.05). Southeast Asian and African children were 1.58 (95% CI = [1.06, 2.35]) and 1.61 (95% CI = [1.17, 2.21]) times more likely, respectively, to consume takeaway foods at least once per week than non-CALD children.

Conclusions

Disparities in overweight/obesity prevalence and obesity-related dietary behaviours among children in Victoria suggest the need for cultural-specific, tailored prevention and intervention strategies.

Campbelltown - Changing our Future: study protocol for a whole of system approach to childhood obesity in South Western Sydney

BACKGROUND

In Australia, around 67% of adults and 25% of children (5-17 years) are currently overweight or obese (Australian Bureau of Statistics, 4364.0.55.001 - National Health Survey: First Results, 2017-18, 2018). The Campbelltown - Changing our Future study will translate 'a whole of system' approach, previously trialed in rural communities in Victoria and the Australian Capital Territoty, to Campbelltown Local Government Area (LGA), a socioeconomically and ethnically diverse urban community in south western Sydney, NSW.

METHODS

The study intervention will use a five-step approach; 1 - set up a childhood obesity monitoring system by collecting baseline data from children in primary schools across Campbelltown LGA to give a local context to the community when developing the systems map; 2 - key stakeholders develop systems maps which inform the development of the interventions; 3 - key stakeholders and community groups identify priority areas for action and form working groups; 4 - implementation of the interventions; 5 - evaluation of the interventions. The study will adopt a longitudinal pre/post design with repeated measures at baseline, 2 years and 4 years. Both qualitative and quantitative methods will be used to collect and analyse the data.

DISCUSSION

Addressing childhood overweight and obesity is complex and requires a multifaceted intervention. This approach has the capacity to impact a range of factors that influence childhood overweight and obesity utilising existing capacity of multiple partners with broad community reach. Findings will develop local responses which capture the complexity of obesity at a community level and further our understanding of the interrelationships and relative importance of local factors impacting childhood overweight and obesity. This study aims to provide evidence for systems methods and approaches suitable for adaption and scaling and may provide evidence of successful community intervention elements.

Establishing a sustainable childhood obesity monitoring system in regional Victoria

Issue addressed Childhood obesity poses a significant immediate and long-term burden to individuals, societies and health systems. Infrequent and inadequate monitoring has led to uncertainty about trends in childhood obesity prevalence in many countries. High-quality data, collected at regular intervals, over extended timeframes, with high response rates and timely feedback are essential to support prevention efforts. Our aim was to establish a sustainable childhood obesity monitoring system in regional Australia to collect accurate anthropometric and behavioural data, provide timely feedback to communities and build community engagement and capacity. Methods All schools from six government regions of South-West Victoria were invited to participate. Passive (opt-out) consent was used to collect measured anthropometric and self-reported behavioural data from children in years 2, 4, and 6, aged 7-12 years. Results We achieved a 70% school participation rate (n=46) and a 93% student response rate (n=2198) among government and independent schools. Results were reported within 10 weeks post data collection. Harnessing high levels of community engagement throughout the planning, data collection and reporting phases increased community capacity and data utility. Conclusions The monitoring system achieved high response rates, community engagement and community capacity building, and delivered results back to the community in a timely manner. So what? This system has the potential to provide sustainable monitoring of childhood obesity that is not dependent on external funding. The results of this monitoring will likely inform health promotion efforts in communities across the region.

Evaluation of complex community-based childhood obesity prevention interventions

BACKGROUND

Multi-setting, multi-component community-based interventions have shown promise in preventing childhood obesity; however, evaluation of these complex interventions remains a challenge.

OBJECTIVE

The objective of the study is to systematically review published methodological approaches to outcome evaluation for multi-setting community-based childhood obesity prevention interventions and synthesize a set of pragmatic recommendations.

METHODS

MEDLINE, CINAHL and PsycINFO were searched from inception to 6 July 2017. Papers were included if the intervention targeted children ≤18 years, engaged at least two community sectors and described their outcome evaluation methodology. A single reviewer conducted title and abstract scans, full article review and data abstraction. Directed content analysis was performed by three reviewers to identify prevailing themes.

RESULTS

Thirty-three studies were included, and of these, 26 employed a quasi-experimental design; the remaining were randomized control trials. Body mass index was the most commonly measured outcome, followed by health behaviour change and psychosocial outcomes. Six themes emerged, highlighting advantages and disadvantages of active vs. passive consent, quasi-experimental vs. randomized control trials, longitudinal vs. repeat cross-sectional designs and the roles of process evaluation and methodological flexibility in evaluating complex interventions.

CONCLUSIONS

Selection of study designs and outcome measures compatible with community infrastructure, accompanied by process evaluation, may facilitate successful outcome evaluation.

Networks for prevention in 19 communities at the start of a large-scale community-based obesity prevention initiative

Community-based obesity prevention efforts are dependent on the strength and function of collaborative networks across multiple community members and organizations. There is little empirical work on understanding how community network structure influences obesity prevention capacity. We describe network structures within 19 local government communities prior to a large-scale community-based obesity prevention intervention, Healthy Together Victoria, Australia (2012-2015). Participants were from a large, multi-site, cluster randomized trial (cRCT) of a whole-of-systems chronic disease prevention initiative. Community leaders from 12 intervention and seven comparison (non-intervention) regions identified and described their professional networks in relation to dietary, physical activity, and weight status among young children (<5 years of age). Social network measures of density, modularity, clustering, and centrality were calculated for each community. Comparison of means and tests of association were conducted for each network relationship. One-hundred and seven respondents (78 intervention; 29 comparison) reported on 996 professional network relationships (respondent average per region: 10 intervention; 8 comparison). Networks were typically sparse and highly modular. Networks were heterogeneous in size and relationship composition. Frequency of interaction, close and influential relationships were inversely associated with network density. At baseline in this cRCT there were no significant differences between community network structures of key actors with influence over environments affecting children's diet and physical activity. Tracking heterogeneity in both networks and measured outcomes over time may help explain the interaction between professional networks and intervention effectiveness of community-based obesity prevention.

Protocol for an economic evaluation of WHO STOPS childhood obesity stepped-wedge cluster randomised controlled trial

INTRODUCTION

Prevention of overweight and obesity in childhood is a priority because of associated acute and chronic conditions in childhood and later in life, which place significant burden on health systems. Evidence suggests prevention should engage a range of actions and actors and target multiple levels. The Whole of Systems Trial Of Prevention Strategies for childhood obesity (WHO STOPS) will evaluate the outcomes of a novel systems-based intervention that aims to engage whole communities in a locally led multifaceted response. This paper describes the planned economic evaluation of WHO STOPS and examines the methodological challenges for economic evaluation of a complex systems-based intervention.

METHODS AND ANALYSIS

Economic evaluation alongside a stepped-wedge cluster randomised controlled trial in regional and rural communities in Victoria, Australia. Cost-effectiveness and cost-utility analyses will provide estimates of the incremental cost (in $A) per body mass index unit saved and quality adjusted life year gained. A Markov cohort model will be employed to estimate healthcare cost savings and benefits over the life course of children. The dollar value of community resources harnessed for the community-led response will be estimated. Probabilistic uncertainty analyses will be undertaken to test sensitivity of results to plausible variations in all trial-based and modelled variables. WHO STOPS will also be assessed against other implementation considerations (such as sustainability and acceptability to communities and other stakeholders).

ETHICS AND DISSEMINATION

The trial is registered by the Australian New Zealand Clinical Trials Registry (ACTRN12616000980437). Full ethics clearances have been received for all methods described below: Deakin University's Human Research Ethics Committee 2014-279, Deakin University's Human Ethics Advisory Group-Health (HEAG-H) HEAG-H 194_2014, HEAG-H 17 2015, HEAG-H 155_2014, HEAG-H 197_2016, HEAG-H 118_2017, the Victorian Department of Education and Training 2015_002622 and the Catholic Archdiocese of Ballarat. Trial findings (including economic evaluation) will be published in peer-reviewed journals and presented at international conferences. Collected data and analyses will be made available in accordance with journal policies and study ethics approvals. Results will be presented to relevant government authorities with an interest in cost-effectiveness of these types of interventions.

TRIAL REGISTRATION NUMBER

ACTRN12616000980437; Pre-results.

Active (Opt-In) Consent Underestimates Mean BMI-z and the Prevalence of Overweight and Obesity Compared to Passive (Opt-Out) Consent. Evidence from the Healthy Together Victoria and Childhood Obesity Study

Background: Tracking population trends in childhood obesity and identifying target areas for prevention requires accurate prevalence data. This study quantified the magnitude of non-participation bias for mean Body Mass Index-z scores and overweight/obesity prevalence associated with low (opt-in) compared to high (opt-out) participation consent methodologies. Methods: Data arose from all Local Government Areas (LGAs) participating in the Healthy Together Victoria Childhood Obesity Study, Australia. Primary schools were randomly selected in 2013 and 2014 and all Grades 4 and 6 students (aged approx. 9-12 years) were invited to participate via opt-in consent (2013) and opt-out consent (2014). For the opt-in wave N = 38 schools (recruitment rate (RR) 24.3%) and N = 856 students participated (RR 36.3%). For the opt-out wave N = 47 schools (RR 32%) and N = 2557 students participated (RR 86.4%).

OUTCOMES

differences between opt-in and opt-out sample estimates (bias) for mean BMI-z, prevalence of overweight/obesity and obesity (alone). Standardized bias (Std bias) estimates defined as bias/standard error are reported for BMI-z. Results: The results demonstrate strong evidence of non-participation bias for mean BMI-z overall (Std bias = -4.5, p < 0.0001) and for girls (Std bias = -5.4, p < 0.0001), but not for boys (Std bias = -1.1, p = 0.15). The opt-in strategy underestimated the overall population prevalence of overweight/obesity and obesity by -5.4 and -4.5 percentage points respectively (p < 0.001 for both). Significant underestimation was seen in girls, but not for boys. Conclusions: Opt-in consent underestimated prevalence of childhood obesity, particularly in girls. Prevalence, monitoring and community intervention studies on childhood obesity should move to opt-out consent processes for better scientific outcomes.

Understanding a successful obesity prevention initiative in children under 5 from a systems perspective

Introduction/Background

Systems thinking represents an innovative and logical approach to understanding complexity in community-based obesity prevention interventions. We report on an approach to apply systems thinking to understand the complexity of a successful obesity prevention intervention in early childhood (children aged up to 5 years) conducted in a regional city in Victoria, Australia.

Methods

A causal loop diagram (CLD) was developed to represent system elements related to a successful childhood obesity prevention intervention in early childhood. Key stakeholder interviews (n = 16) were examined retrospectively to generate purposive text data, create microstructures, and form a CLD.

Results

A CLD representing key stakeholder perceptions of a successful intervention comprised six key feedback loops explaining changes in project implementation over time. The loops described the dynamics of collaboration, network formation, community awareness, human resources, project clarity, and innovation.

Conclusion

The CLD developed provides a replicable means to capture, evaluate and disseminate a description of the dynamic elements of a successful obesity prevention intervention in early childhood.

Whole of Systems Trial of Prevention Strategies for Childhood Obesity: WHO STOPS Childhood Obesity

Background: Community-based initiatives show promise for preventing childhood obesity. They are characterized by community leaders and members working together to address complex local drivers of energy balance. Objectives: To present a protocol for a stepped wedge cluster randomized trial in ten communities in the Great South Coast Region of Victoria, Australia to test whether it is possible to: (1) strengthen community action for childhood obesity prevention, and (2) measure the impact of increased action on risk factors for childhood obesity. Methods: The WHO STOPS intervention involves a facilitated community engagement process that: creates an agreed systems map of childhood obesity causes for a community; identifies intervention opportunities through leveraging the dynamic aspects of the system; and, converts these understandings into community-built, systems-oriented action plans. Ten communities will be randomized (1:1) to intervention or control in year one and all communities will be included by year three. The primary outcome is childhood obesity prevalence among grade two (ages 7-8 y), grade four (9-10 y) and grade six (11-12 y) students measured using our established community-led monitoring system (69% school and 93% student participation rate in government and independent schools). An additional group of 13 external communities from other regions of Victoria with no specific interventions will provide an external comparison. These communities will also allow us to assess diffusion of the intervention to control communities during the first three years of the trial. Conclusion: This trial will test effectiveness, over a five-year period, of community-owned, -supported and -led strategies designed to address complex and dynamic causes of childhood obesity.

Composition of objectively measured physical activity and sedentary behaviour participation across the school-day, influence of gender and weight status: cross-sectional analyses among disadvantaged Victorian school children

BACKGROUND

The after-school period has been described as the 'critical window' for physical activity (PA) participation. However, little is known about the importance of this window compared with the before and during-school period among socioeconomically disadvantaged children, and influence of gender and weight status.

METHODS

39 out of 156 (RR=25%) invited primary schools across 26 local government areas in Victoria, Australia, consented to participate with 856 children (RR=36%) participating in the wider study. The analysis sample included 298 Grade 4 and Grade 6 children (mean age: 11.2±1.1; 44% male) whom met minimum accelerometry wear-time criteria and had complete height, weight and health-behaviours questionnaire data. Accelerometry measured duration in daily light-intensity PA (LPA), moderate-to-vigorous PA (MVPA) and sedentary time (ST) was calculated for before-school=8-8:59, during-school=9:00-15:29 and after-school=15:30-18:00. Bivariate and multivariable linear regression analyses were conducted.

RESULTS

During-school represented the greatest accumulation of LPA and MVPA compared with the before and after-school periods. Boys engaged in 102 min/day of LPA (95% CI 98.5 to 104.9) and 62 min/day of MVPA (95% CI 58.9 to 64.7) during-school; girls engaged in 103 min/day of LPA (95% CI 99.7 to 106.5) and 45 min/day of MVPA (95% CI 42.9 to 47.4). Linear regression models indicated that girls with overweight or obesity engaged in significantly less LPA, MVPA and more time in ST during-school.

CONCLUSIONS

This study highlights the importance of in-school PA compared with after-school PA among socioeconomically disadvantage children whom may have fewer resources to participate in after-school PA.