Advancing the science of policy implementation: a call to action for the implementation science field

Public policies have been essential in addressing many of the most pressing public health problems in the USA and around the world. A large and convincing body of multidisciplinary research has established the impacts or effectiveness of public policies, such as smoke-free air laws and nutrition standards, on improving health outcomes and behaviors. Most of this research assumes that because an evidence-based policy is adopted or takes effect, it is implemented as intended. This assumption, however, is often incorrect. Like with clinical guidelines and other interventions, implementation science has an important role to play in promoting the uptake and implementation of evidence-based public policies that promote public health. To realize this potential, there remains a critical need to first establish a common understanding of what public policy is, the role of specific policies in the context of implementation (i.e., is it the evidence-based intervention or the implementation strategy?), and to establish an appropriate methodological foundation for the field of policy implementation science. We recommend that the field must evolve to (i) include policy experts and actors on policy implementation science study teams; (ii) identify theories, models, and frameworks that are suitable for policy implementation science; (iii) identify policy implementation strategies; (iv) adapt and/or identify study designs best suited for policy implementation science research; and (v) identify appropriate policy implementation outcome measures. Lay summary Public policies are important to promote the health and well-being of the public. Many important health advances have been made because of policies designed to prevent or limit unhealthy behaviors (such as smoke-free laws) and promote access to medical care (such as health insurance mandates). However, just because a policy is "on the books" does not mean that it is implemented or implemented as intended. To improve how researchers study policy implementation, we discuss some challenges in the field, provide a call to action for researchers to continue developing the field of policy implementation science, and we recommend that scientists establish partnerships with experts in public policy and work together to develop scientific methods that will do a better job of putting policy into practice.