[The scientific evidence. A strategy for nursing practice].

As in any professional field, nursing practice based on evidence deals with the application of decisions based on the best available scientific testing data. Carrying out one's professional obligations in accordance with the best evidence is a demand society requires which is valid for all human behavior and is an essential ethical component in any profession. In this article, the elements of scientific evidence are presented; the steps to follow in the application of this evidence are described; and lastly, there is an analysis of the reasons which justify the implementation of these steps in nursing practice.