Systems Thinking to Improve the Public's Health

Abstract

Improving population health requires understanding and changing societal structures and functions, but countervailing forces sometimes undermine those changes, thus reflecting the adaptive complexity inherent in public health systems. The purpose of this paper is to propose systems thinking as a conceptual rubric for the practice of team science in public health, and transdisciplinary, translational research as a catalyst for promoting the functional efficiency of science. The paper lays a foundation for the conceptual understanding of systems thinking and transdisciplinary research, and will provide illustrative examples within and beyond public health. A set of recommendations for a systems-centric approach to translational science will be presented.

Introduction

“Public health asks of systems science, as it did of sociology 40 years ago, that it help us unravel the complexity of causal forces in our varied populations, and the ecologically layered community and societal circumstances of public health practice.”¹

Green's quote suggests that to improve public health, it will be necessary to gain a greater understanding of the complex adaptive systems involved in both causing and solving public health problems.² For example, preventing and containing pandemic influenza requires collaboration across a wide array of disciplines and fields, including global surveillance to catch new outbreaks, rapid laboratory analysis of new viral strains so that effective medications can be developed, and the creation of expansive communications and informatics infrastructures so that communities can prepare and react effectively. Each separate activity to address pandemic influenza is necessary but insufficient in itself. However, when viewed together, the structures and functions to prevent and contain pandemic influenza represent an ever-changing complex adaptive system whose sum is greater than the parts. Indeed, millions—and perhaps billions—of lives depend on how well that complex system works.

The increasing emphasis on systems thinking as an organizing rubric reflects a confluence of trends among very different fields that have begun to emphasize systems thinking, including business, engineering, physics, military science, agriculture, weather forecasting and public health.3, 4 While there is no single discipline for systems thinking, there are some fundamental systems-thinking perspectives and approaches that are shared across fields: (1) increased attention to how new knowledge is gained, managed, exchanged, interpreted, integrated, and disseminated; (2) emphasis on a network-centric approach that encourages relationship-building among and between individuals and organizations across traditional disciplines and fields in order to achieve relevant goals and objectives; (3) the development of models and projections, using a variety of analytic approaches (e.g., differential equations, agent-based modeling, system-dynamics modeling) in order to improve strategic decision making; and (4) systems organizing in order to foster improvements in organizational structures and functions.2, 3, 4

Consistent with this systems perspective, and echoing Rosenfield's⁵ benchmark definitions of multidisciplinarity, interdisciplinarity, and transdisciplinarity, Stokols⁶ in this supplement to the American Journal of Preventive Medicine describes transdisciplinary research as a “process in which team members representing different fields work together over extended periods to develop shared conceptual and methodologic frameworks that not only integrate but also transcend their respective disciplinary perspectives.” Given the profoundly different ways that scientists collect data and define new knowledge within disciplines, along with the many different discipline-based assumptions about the nature of that knowledge, transdisciplinarity reflects an epistemology, or theory of knowledge, that has profound implications for how new knowledge is collected, synthesized, interpreted, and disseminated. This is not to suggest that unidisciplinary, reductionist science is no longer relevant. Rather, the increased emphasis on science that is transdisciplinary, translational, and network-centric reflects a recognition that much, if not most, disease causation is multifactorial, dynamic, and nonlinear.⁷ Indeed, scientific silos, or compartmentalized knowledge, have the potential to impede understanding of the complex inter-relationships among variables.⁸

It is perhaps neither possible nor desirable to eliminate the silos of science, but there is increasing recognition that it is essential to link them and to recognize that they represent components of a larger system.² That is, transdisciplinary science represents a necessary but insufficient aspect of complex adaptive public health systems. Achieving effective and lasting advances in public health clearly depends on the knowledge gained through transdisciplinary science (e.g., the biological and behavioral causes of tobacco dependence, or social and biological factors that cause the spread of communicable diseases). But achieving those gains also requires making strategic decisions about which complex scientific questions will lead to the greatest public health gains, how new discoveries can be disseminated effectively, and what structures and functions are needed to deliver the new knowledge. The opinion that complex challenges cannot be solved by reductionist approaches alone reflects an orientation toward systems thinking that Senge⁹ called a “fifth discipline.” And this fifth discipline is highly consistent with the principles of systems thinking and cybernetics that were discussed long ago by von Bertalanffy,10, 11 Wiener,¹² and Ackoff,¹³ and more recently by Leischow and Milstein,² Sterman,¹⁴ Midgely,¹⁵ and Green.¹