The value of a causal loop diagram in exploring the complex interplay of factors that influence health promotion in a multisectoral health system in Australia

Background Despite calls for the application of complex systems science in empirical studies of health promotion, there are very few examples. The aim of this paper was to use a complex systems approach to examine the key factors that influenced health promotion (HP) policy and practice in a multisectoral health system in Australia. Methods Within a qualitative case study, a schema was developed that incorporated HP goals, actions and strategies with WHO building blocks (leadership and governance, financing, workforce, services and information). The case was a multisectoral health system bounded in terms of geographical and governance structures and a history of support for HP. A detailed analysis of 20 state government strategic documents and interviews with 53 stakeholders from multiple sectors were completed. Based upon key findings and dominants themes, causal pathways and feedback loops were established. Finally, a causal loop diagram was created to visualise the complex array of feedback loops in the multisectoral health system that influenced HP policy and practice. Results The complexity of the multisectoral health system was clearly illustrated by the numerous feedback mechanisms that influenced HP policy and practice. The majority of feedback mechanisms in the causal loop diagram were vicious cycles that inhibited HP policy and practice, which need to be disrupted or changed for HP to thrive. There were some virtuous cycles that facilitated HP, which could be amplified to strengthen HP policy and practice. Leadership and governance at federal–state–local government levels figured prominently and this building block was interdependently linked to all others. Conclusion Creating a causal loop diagram enabled visualisation of the emergent properties of the case health system. It also highlighted specific leverage points at which HP policy and practice can be improved. This paper demonstrates the critical importance of leveraging leadership and governance for HP and adds urgency to the need for increased and strong advocacy efforts targeting all levels of government in multisectoral health systems. Electronic supplementary material The online version of this article (10.1186/s12961-018-0394-x) contains supplementary material, which is available to authorized users.