Clarity out of chaos: Use of theory in implementation research.

Implementation science has been recognized as a potential catalyst for health system reform, in part, because of its contribution of well-grounded conceptual theories, often encapsulated in frameworks. Well-designed frameworks provide a semantic structure, a common language by which to guide systematic approaches to studying implementation and testing interventions. An overview of the types and roles of theory in advancing implementation science is offered in this article. Resources for selecting appropriate frameworks are described along with illustrative examples. The case is made that well-developed theory is what enables knowledge to emerge out of seeming chaos and for translation of that knowledge to be widely and reliably implemented into routine practice so that health and well-being of patients is maximized by delivery of interventions that are rooted in that knowledge.