Systems thinking in Public Health

What is systems thinking?

Many public health challenges, such as poor mental health, obesity, long-term conditions and climate change, are shaped by many connected factors. Systems thinking helps us understand those connections and work with partners to create lasting improvements in health and wellbeing across Wales.

Systems thinking can help us think about the bigger picture, much like a doctor seeing beyond a patient’s symptoms and considering their whole life, or a gardener considering the conditions in the environment around a plant. We look at the inter-relationships between parts of the system, thinking about where somebody lives, their level of income and how their access to transport may interact to affect health.

Within Public Health Wales, systems thinking can involve:

• bringing together people from different sectors and backgrounds to understand different perspectives on an issue
• being clear about what is included and excluded from an intervention (boundary judgements)
• exploring the root causes of problems
• understanding the relationships between different parts of a system

When using systems thinking to make improvements, we must make time for on-going reflection, learning and adaptation. Complex issues are unpredictable, and when we intervene to make improvements, we don’t always know what the outcome of our action will be. This means we must find ways to check whether our intervention is having the intended effect and respond accordingly.

By using systems thinking we are also using the Well-being of Future Generations’ Sustainable Development Principle’s five Ways of Working – Integration, Prevention, Collaboration, Long- Term Thinking and Involvement.

Why is systems thinking needed?

Improving health outcomes is often complex. Our health is shaped by many factors; from the education we receive to whether we have a job that pays enough to cover the bills.

The building blocks of health are the things that we all need to be healthy, such as warm homes, good work, safe neighbourhoods with green space and a good support network.

To deliver the priorities of Public Health Wales we regularly need to influence many of these building blocks at once to address some of the complex challenges facing Wales, from poor mental health in some young people to non-communicable diseases (such as cardiovascular disease and cancer) and adapting to climate change.

To address these complex challenges requires us to bring together partners from across organisations and sectors to work collaboratively, creating a shared vision for how we want to improve the lives of our communities in Wales and look at the relationships between these building blocks of health. For example, people with poor mental health are also more likely to develop non-communicable diseases ^[i].

Working with this complexity means we must see the whole rather than focus on isolated parts. We must develop long-term plans that are also able to adapt to a changing context, and we must ensure we are including diverse perspectives, from other partners but also from different communities across Wales. Systems thinking is a way of thinking and working which can help us do this.

Related concepts

A system is a collection of connected parts that work together. Changes to one part of a system can influence how the whole system behaves. People may have different views about what should be included within a system.

Systems thinking approaches include a range of tools and methods we can use to better understand the complexity and inter-dependencies of public health issues. Some common tools include systems mapping, rich pictures or the iceberg model.

Systems leadership is a style of leadership that focuses on collaborating and influencing across multiple levels, organisations or sectors to address complex and interconnected challenges. Key to systems leadership in a public health context is driving ‘positive change’ on a broad scale, developing joined up solutions to complex public health issues for the benefit of society^[ii].

How is Public Health Wales using systems thinking approaches

Anyone can use systems thinking, but within Public Health Wales, a number of programmes have focused resources to develop systems thinking and commit to taking a systems thinking approach.

• Healthy Weight Healthy Wales Whole Systems Approach – supports healthier weight by reshaping ways of working, policies and environments to create lasting solutions that make healthy options easier, more affordable and more accessible.
• Shaping Places for Well-being in Wales – Funded by the Health Foundation and seeks to build systems thinking capability within Public Services Boards supporting them to deliver actions through their well-being plans.

[i] Everard, C. et al. (2025), “Exploring the relationship between non-communicable diseases and depression”, OECD Health Working Papers, No. 178, OECD Publishing, Paris, https://doi.org/10.1787/02a1cfc5-en.

[ii] PHW Skills for Public Health Systems Leadership Report