According to the four concepts common in nursing theory; the person (patient), the environment, health & nursing (goals, roles, functions) can be analyzed. Each of these concepts is usually defi ned and described by a nursing theorist. Of the four concepts, the most important is that of the person. The four concepts are generally considered central to the discipline of nursing.
https://courses.lumenlearning.com/suny-delhi-professionalnursing/chapter/nursing-theory/
Classifications of middle range theories
