This glossary includes resources and definitions of wider determinants of health, complex systems and systems thinking approaches.
Wider determinants of health
The wider (or social) determinants of health (The need for a complex systems model of evidence for public health, The Lancet, paywall) are the social, economic, environmental and commercial factors that shape the conditions in which are born, grow, live, work and age.
“A complex systems model of public health conceptualises poor health and health inequalities as outcomes of a multitude of interdependent elements within a connected whole. These elements affect each other in sometimes subtle ways, with changes potentially reverberating throughout the system.” This means seeing a health outcome or issue or inequality as a result of a large number of interacting factors that form a ‘complex system’. Changes in any single part of this system can have wide-reaching and unpredictable effects right across the system.
Characteristics of a complex system
Complex systems are defined by several properties:
- Emergence describes the properties of a complex system that cannot be directly predicted from the elements within it and are more than just the sum of its parts. e.g. obesity in a population can be understood as an emergent property of the food, employment, transport, economic, and other systems that shape the food intake and physical activity of individuals.
- Feedback describes the situation in which a change reinforces or balances further change. e.g. if a smoking ban in public places reduces the visibility and convenience of smoking, and this makes it less appealing, fewer young people might then start smoking, further reducing its visibility, and so on in a reinforcing loop.
- Adaptation refers to adjustments in behaviour in response to interventions e.g. a tobacco company lowering the price of cigarettes in response to a public smoking ban.
Systems approaches encourage looking at a bigger picture, and thinking about:
- How different individuals, populations, organisations and sectors relate to each another.
- How specific activities and changes in one part of a system may affect other parts, sometimes in unexpected ways.
- How to bring more synergy and coherence to different activities.
This requires a different way of doing things, and a complex systems approach uses a wide range of ways of designing, implementing, and evaluating interventions for changing these systems to improve public health.