Building consensus and guiding action: A ‘what if’ tool for tackling wicked problemsModelling childhood overweight and obesity interventions
Presented by Nick Roberts and Vincy Li World Congress on Public Health 2017
Childhood overweight and obesity (COO)
• Childhood overweight and obesity is a key issue – Increasing prevalence – Lasting effects on individuals, society and economy
• Around 1 in 4 children are currently overweight or obese in Australia
• In 2015, the NSW Premier unveiled 12 Premier’s Priorities. One was to reduce the prevalence of overweight and obesity in children aged 5–16 years by 5% over 10 years in NSW
COO is challenging to address• Childhood overweight and obesity is a complex issue
– A large number of multi‐level risk factors contribute to the problem – Numerous potential points of intervention
• There is a broad range of intervention options but little is known about combined effect of different interventions
• OUR MISSION! To develop a model to test how we might address childhood overweight and obesity and achieve the Premier’s target
• Using computer models as simplified representations of real world
• Capturing population and behavioural dynamics, feedback loops, effects of interventions over time and interaction of risk factors
• Long history of use in engineering, maths, climate science
depressionWeight gain
Example of feedback loop
Example SD model (Sterman 2001)
What is System Dynamics (SD) modelling?
• Provides a framework for mapping and quantifying the complex problem of childhood overweight and obesity
Why did we use SD modelling?
• Allows us to test (in a low cost and risk free way) the likely impacts and costs of different options for intervening before implementing our ‘solutions’ in the real world
• Can inform how best to invest limited resources to achieve the health targets.
• Initial model developed Jul‐Dec 2016 • Participatory method – experts in
policy, academia, service delivery, and modelling contributed to development over three workshops.
Our methods – how we used SD modelling
• During the three workshops:– Collaborative development of model structure,
mapping factors driving childhood overweight and obesity
– Prioritisation of interventions for model and mapping where and how they have effect
– Validated mechanisms by which interventions have effect
– Participants tested the model and provided feedback
Our methods – How we used SD modelling
Various data sources were used in the model
Childhood overweight & obesity model
Systematic review / meta analysis evidence
Other peer reviewed literature
Outcomes of existing interventions
O&O prevalence data, population projections
Expert opinion, consensus
The model in 60 seconds!
• Theoretically, it appears to be possible to reduce the prevalence of childhood overweight and obesity in NSW by 5% over 10 years (i.e. end of 2025/early 2026)
• It will take the full suite of modelled interventions (individual and settings‐based programs, environmental changes, policies, social marketing campaign) to achieve the target within this timeframe
• The earliest we might see even a small (1%) reduction is 2020/2021
Key insights from the model
• A tool that allows us to navigate through complex problems and test different scenarios to provide insights
• A platform for drawing together disparate sources of data and evidence to inform decision making
• A way of making clear assumptions that are often implicit, allowing us to think through and question them, and identifying gaps in the existing evidence base
What we have built
• Building costs into the model and conducting sensitivity analyses
• Equity considerations: socioeconomic status, urban / rural, culturally and linguistically diverse groups
Potential next steps
Thank you Core model building group Jo‐An Atkinson
Nick Roberts
Vincy Li
Mark Heffernan
Geoff McDonnell
Other abstract co‐authors: Eloise O’Donnell
Sonia Wutzke
Bev Lloyd
Jo Mitchell
Our expert model building participants, from:
NSW Ministry of Health
NSW Health
NSW Department of Premier and Cabinet
NSW Department of Education and Communities
NSW Treasury
NSW Office of Preventive Health
TAPPC
The Sax Institute
University of Sydney
Queensland University of Technology
University of Wollongong
George Institute for Global Health
Deakin University
VIC Department of Health and Human Services
University of Newcastle
ACT Health
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