Cited from "What is outcomes research and what can it tell us?" Carl H. Slater , Evaluation & The professions, Vol 20 No.3, September 1997
Considering structure, process, and outcomes, outcomes research also related to any and all of four different levels of analysis:
Community, System, institution or patients
Structure is "the settings in which it (medical care) takes place and the instrumentalities of which it is the product".