Guidance on the Use of Complex Systems Models for Economic Evaluations of Public Health Interventions

Objectives: To help health economic modellers respond to demands for greater use of complex systems models in public health. To propose identifiable features of such models and support researchers to plan public health modelling projects using these models. Methods: A working group of experts in complex systems modelling and economic evaluation was brought together to develop and jointly write guidance for the use of complex systems models for health economic analysis. The content of workshops was informed by a scoping review. Results: A public health complex systems model for economic evaluation is defined as a quantitative, dynamic, non-linear model that incorporates feedback and interactions among model elements, in order to capture emergent outcomes and estimate health, economic and potentially other consequences to inform public policies. The guidance covers: when complex systems modelling is needed; principles for designing a complex systems model; and how to choose an appropriate modelling technique. Conclusions: This paper provides a definition to identify and characterise complex systems models for economic evaluations and proposes guidance on key aspects of the process for health economics analysis. This document will support the development of complex systems models, with impact on public health systems policy and decision making.