Four very basic ways to think about policy in implementation science

BACKGROUND: Policy is receiving increasing attention in the field of implementation science. However, there remains a lack of clear, concise guidance about how policy can be conceptualized in implementation science research. Building on Curran's article "Implementation science made too simple"-which defines "the thing" as the intervention, practice, or innovation in need of implementation support-we offer a typology of four very basic ways to conceptualize policy in implementation science research. We provide examples of studies that have conceptualized policy in these different ways and connect aspects of the typology to established frameworks in the field. The typology simplifies and refines related typologies in the field. Four very basic ways to think about policy in implementation science research. 1) Policy as something to adopt: an evidence-supported policy proposal is conceptualized as "the thing" and the goal of research is to understand how policymaking processes can be modified to increase adoption, and thus reach, of the evidence-supported policy. Policy-focused dissemination research is well-suited to achieve this goal. 2) Policy as something to implement: a policy, evidence-supported or not, is conceptualized as "the thing" and the goal of research is to generate knowledge about how policy rollout (or policy de-implementation) can be optimized to maximize benefits for population health and health equity. Policy-focused implementation research is well-suited to achieve this goal. 3) Policy as context to understand: an evidence-supported intervention is "the thing" and policies are conceptualized as a fixed determinant of implementation outcomes. The goal of research is to understand the mechanisms through which policies affect implementation of the evidence-supported intervention. 4) Policy as strategy to use: an evidence-supported intervention is "the thing" and policy is conceptualized as a strategy to affect implementation outcomes. The goal of research is to understand, and ideally test, how policy strategies affect implementation outcomes related to the evidence-supported intervention. CONCLUSION: Policy can be conceptualized in multiple, non-mutually exclusive ways in implementation science. Clear conceptualizations of these distinctions are important to advancing the field of policy-focused implementation science and promoting the integration of policy into the field more broadly.