Population health intervention research: advancing the field.

entire populations and to reduce health inequities.* It recognizes both health as a capacity or resource and the range of social, economic and environmental factors that contribute to it. A related articulation of health is “the capacity of people to adapt to, respond to, or control life’s challenges and changes”.1 In their seminal paper, Hawe and Potvin2 raise a cogent related question, “what is population health intervention research (PHIR)?” They argue that population-level health interventions are policies or programs that shift distributions of health risk by addressing underlying social, economic and environmental issues. These interventions might be programs or policies designed/developed in the health sector, but more likely in education, housing or employment. PHIR aims to capture the value and differential effects of interventions, the processes by which they create change, and the contexts within which they work best. Further, Hawe and Potvin call for an integration of learning to assist in development of the PHIR field. They go on to highlight that the Population Health Intervention Research Initiative for Canada (PHIRIC) defines PHIR as research that “involves the use of scientific methods to produce knowledge about policy/program interventions that operate within or outside of the health sector and have potential to impact health at a population level.” “Population health” refers to the science underpinning the practice of public health and understandings about health that come from an appreciation of how it is generated in populations. An additional aspect is that of “impact at a population level”. This involves not simply improving health or reducing health risks, but implementing interventions to change risk conditions in order to alter distributions of health risk. We concur with Hawe and Potvin that “all systematic inquiry and learning from observing an intervention’s process or implementation, impact or outcome is encompassed in ‘intervention research’.” Evaluation research and PHIR encompass many of the same activities and methods. All evaluation research in population health is PHIR, but not all population health intervention research is evaluation research. Hawe and Potvin conclude that “the ever-growing burden of disease demands that we design effective interventions and put them into practice”.2 This Special Supplement, consisting of nine research papers, is offered as a modest “ brick in the wall” of Canada’s population health agenda. It is based in the reality that the concept of PHIR continues to gain ground and that there is growing interest and concern among researchers and policy-makers to better identify effective and efficient interventions. The Supplement aims to address this need by featuring PHIR from around the world. It contains an invited article by Dr. John Frank, the nine research papers, and a brief epilogue by Dr. Louise Potvin (Co-Principal Investigator of the PHIR Network Training Program). The selection process was rigorous and involved an international call for outlines of potential papers, a relevance review of the outlines by a Supplement Editorial Committee (see Acknowledgements), an invitation from the Committee to selected authors to submit full papers, and a final relevance review of full papers by the Committee. All invited papers were then submitted online and underwent CJPH’s standard peer-review process. The call was advertised through academic/professional contacts, networks, associations, educational institutions, and listservs. We encouraged outlines of papers that reported on research from diverse disciplines/sectors on a wide variety of policies or programs designed to improve health at a population level. The 48 outlines received were rated for three “face” characteristics of “prototypical” PHIR, i.e., that it: 1) is a research project; 2) describes an intervention; and 3) aims to improve population health. The outlines were also reviewed based on breadth of coverage in five areas: 1) discipline/sector; 2) conditions of risk; 3) geography; 4) inclusion of community engagement; and 5) language (English/French). The following briefly summarizes each of the nine accepted papers. Rowe et al. examine the effectiveness of an educational policing strategy in New South Wales, Australia to reduce the number of patrons of licensed premises involved in incidents of violence, disorder and motor vehicle crashes. The intervention in 21 nonmetropolitan areas included letters, incident reports, covert audits and feedback meetings. Across all premises, the rate of patrons who consumed alcohol prior to involvement in incidents decreased as a result of the policing strategy. The authors’ findings suggest the benefit of a policing strategy as a possible PHI. Lawless et al. report on the “Health in All Policies” intervention from South Australia. “Health in All Policies” is seen as a means of embedding concern for health impacts in policy-making. The primary mechanism is a “health lens analysis” – an intersectoral process drawing on public health research methods. In this paper, it was applied to water security, digital technology and migration, and appears to have led to increased understanding of the impacts on health outcomes, changes in policy direction, development/dissemination of research, partnerships between health and other government departments, and a positive disposition toward employing health lens analyses in future work. In an interesting African paper, Samb assesses the impact of care subsidies on primary health centres in Burkina Faso. The government subsidizes 80% of emergency neonatal/obstetrical costs, while an NGO subsidizes the remaining 20%. Care subsidies have strengthened community members’ and their primary health centres’ power to act, such as participation in decision-making, as well as knowledge acquisition and skill development. (This article published in French, with translation of abstract.)