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Policy diffusion theory, evidence-informed public health, and public health political science: a scoping review

In public health and healthcare, conventional wisdom often suggests that the availability, accessibility, and appreciation of high-quality scientific evidence will lead to evidence-based public health policy making across government sectors. However, the literature does not support this “linear evidence-to-policy model of policy decision-making” and instead, demonstrates that “the production and dissemination of scientific evidence alone does not have substantive impact on public policymaking”. 

Policy diffusion can be defined as a process “where policy decisions in one jurisdiction influence policymaking in other jurisdictions “. 

In this scoping review, the authors report many instances of policy diffusion in public health policy decision-making.  Mechanisms of policy diffusion including learning, emulation, competition, coercion, and social contagion are at play in the diffusion of public health policies in domains such as anti-smoking and tobacco control, HIV/AIDS, marijuana regulation, and others.

In addition, the review notes that the severity of local public health problems and the presence of scientific evidence did not reliably contribute to policy making actions or inform policy diffusion. 

This research confirms and contributes to the understanding that public health is political and decision making does not rely on the presence of scientific evidence alone. Practitioners in the field must understand political processes as an important part of their practice to be aware of and better prepared for the intergovernmental factors that contribute to decision-making in public health. 

This resource can inform public health’s knowledge translation methods “…to consider what constitutes appropriate and relevant evidence in the policy diffusion process…as opposed to what “should” inform policymaking based on established hierarchies that favour certain types of scientific evidence (e.g., systematic reviews, randomized controlled trials) and their accompanying epistemological perspectives.” (p.341)

Use this resource to:

  • explore the mechanisms of governmental public health policy decision-making, and 
  • consider if and how knowledge translation efforts should be modified to fit a particular policy diffusion mechanism to successfully inform public health policy making.  


Alignment with NCCDH work:

Other resources published by NCCDH point to power as a dimension to be assessed when reflecting on the political processes that influence policymaking. These dimensions include: what policies get considered, who gets to speak about those, what kind of evidence makes it to the decision-making table, and what worldviews influence those decisions.

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See other resources on how public health can participate in healthy public policy development.


Fundytus, K., Santamaria-Plaza, C. & McLaren, L. (2023) Policy diffusion theory, evidence-informed public health, and public health political science: a scoping review. Can J Public Health. Vol. 114. pp. 331–345.

Tags: Healthy public policy, Academic Institution, Document, Journal Article