Shaping a New Field: Three Key Challenges for Population Health Science

As part of the Public Health of Consequence series, the invited editorial by Keyes and Galea^1(p633) contends that population health science (PHS) has the potential to meaningfully address “complex, solution-resistant problems” such as “obesity, addiction, mental health, and new and reemerging infectious diseases” and, in doing so, improve health and reduce health disparities in consequential ways. PHS is a broad, interdisciplinary approach to developing a clearer understanding of the production of health within and across populations. This breadth establishes a new space to integrate a cells-to-society understanding of health; identify important mechanisms, from microscopic to global factors that generate health; and develop multilevel, innovative interventions to improve health.² As have others,³ Keyes and Galea make a compelling case that PHS holds tremendous promise for improving health and reducing health disparities.

In this contribution, we identify three critical challenges that we believe must be thoughtfully pursued to realize the promise of PHS: the meaningful integration of research on macro-level processes in health research, improved mechanisms for responsibly addressing the demand for consequential science, and the development of infrastructure that supports the goals of the field without creating yet another siloed discipline. We introduce a new membership organization, the Interdisciplinary Association for Population Health Science (IAPHS) that provides an essential element of that infrastructure.

Although the emergence of PHS has generated enthusiasm for its potential, there has also been some confusion regarding the nature and boundaries of the approach. A decade ago, some scholars might have used the term “population health” to refer specifically to cost and quality management in the context of health care systems, and others might have used the term to refer to the multiple, overlapping, and complex factors shaping the health of populations. Our language, however, is becoming more precise. Cost and quality management of patient populations is now likely to be described as population health management or population medicine and the key concepts championed by Keyes and Galea as population health or PHS. Even so, enthusiasts for population health may approach the subject with different preconceptions, and this is both a challenge and an invaluable opportunity for an interdisciplinary field.

INTEGRATING MACRO PROCESSES

The growth of PHS reflects the crystallization of a pair of complementary paradigm shifts that have been reshaping traditional approaches to health science. One is the development of interdisciplinary team science, in which complex problems are tackled by combining expertise from many different disciplines.⁴ The other is the recognition that health and patterns in health across time and space are complex and multicausal.

Using insights from team science to leverage a range of disciplinary expertise, PHS must shed light on the ways in which upstream and downstream determinants are produced and interact to produce health or disease. Treating the social and environmental determinants of health simply as exposures or individual risk factors falls short. The social determinants of health are themselves the products of complex systems involving processes of stratification, economic cycles, political movements, institutional and cultural change, diffusion, migration, social interaction, and much more; all of these topics are studied by social scientists in different disciplines. Drilling down to discover micro-level health determinants will be most impactful when coupled with a meaningful understanding of the macro-level processes that shape health.

Although schools of public health are increasingly incorporating social science, partnerships with liberal arts campuses are often essential to engage the necessary expertise. It is well known that such partnerships are challenging for many reasons: institutional boundaries, geography, disciplinary blinders and incentive structures, and much more. But there is much that can be done. The growth in support from both universities and federal funders for interdisciplinary centers and collaborations has done much to change the culture over recent decades; targeting new investments at the interface of health and the social sciences would do more. In addition, there is a need for focused interdisciplinary training, not only exposing trainees to information from different disciplines but providing experience-based training and mentoring in the skills needed to lead and collaborate in interdisciplinary teams.⁵

CREATING CONSEQUENTIAL SCIENCE

Most scientists engaged in population health research are doing it because they want to make a difference in improving health and reducing disparities. Creating conditions that enable research to inform policy and practice and respond to real-time information needs should be a top priority for the field. In previous work,⁶ we called for an interdependent relationship between population health science and practice, one buttressed by agile institutional mechanisms. What would this mean?

The concept of a two-way exchange between scientists and those in a position to apply scientific results is compelling.⁷ The challenge is making room for the exchange on both sides. Scientific training is an intensive process, and academic researchers are not uniformly rewarded for translational activities. In fact, many PHS-relevant disciplines have incentives that constrain applied research and may even conflate application of research results with advocacy. Finding ways to provide basic exposure to, and experience in, issues of translation for researchers and developing workable models for enriching on-the-ground science are both essential.

Community-based participatory research is an obvious and important model, but the field will benefit from investing in a range of ways to be outward facing with its research. Creating more opportunities for meaningful two-way exchanges between national, state, and local policymakers; public health practitioners; and population health scientists may be a first step toward this goal. These types of exchanges provide opportunities to develop more consequential scientific agendas and more effective ways of doing and communicating science.

INFRASTRUCTURE

Our third challenge is developing infrastructure that can support population health as an interdisciplinary field—a practice of connection and collaboration—rather than a discipline with prescribed theories and methods that create boundaries. Many medical and public health schools are creating departments of population health, and it is possible, but not inevitable, that they could be designed to remain flexibly and broadly interdisciplinary. Training programs that extend their reach across university schools and actively teach interdisciplinarity can be effective in ensuring this aim. A report commissioned by the National Academy of Medicine Roundtable on Population Health Improvement provides recommendations and a model for such innovative programs.⁵

Beyond this, a national organization that specifically focuses on PHS and is attuned to the challenges noted here is essential for moving the field forward. We are happy to report that one now exists. In September 2016, the Interdisciplinary Association for Population Health Science opened its doors as a membership organization. IAPHS complements other health organizations such as the American Public Health Association and AcademyHealth by providing an additional professional home exclusively devoted to interdisciplinary PHS. It has already collaborated in a pair of highly successful conferences, funded by the Robert Wood Johnson Foundation, featuring interdisciplinary science and interchange among scientists, policymakers, and practitioners.

IAPHS will be a forum that attracts scientists from all disciplines, supports interdisciplinary exchange and collaboration, and motivates progress toward an integrated, multilevel understanding of health. It is an important professional space that will support its members as interdisciplinary scientists, helping them navigate career challenges. And it will help scientists build effective bridges with policymakers and practitioners who need scientific evidence to guide health investments. We invite readers to visit the Web site (https://iaphs.org), follow us on social media, and engage with a growing community of population health scientists who are committed to advancing the field.