[Guidelines: general principles and clinical application in nephrology]

Clinical practice guidelines (GL) are multiplying and spreading throughout the scientific world. Nephrology is no exception and GL are more often recalled in the daily activity. Therefore, it can be useful to propose an excursus on the issue, to report the most important principles on the base of GL and moreover, to remember that GL are the synthesis between the scientific evidences published in literature and the critical analysis performed by an international committee of experts. Not all GL have the same clinical value. As a matter of fact, GL have a different strength of recommendation and grading according to the clinical evidences published. The number and methodological accuracy of the available studies on a specific subject are crucial to define the quality, the grading and the strength of GL. GL must also be shared with a wide number of specialists and other interested people such as patient organizations as well as health political institutions. Although the knowledge of GL is widespread, their practical use is still limited. The spreading of the knowledge regarding how GL are arranged, their appropriate reading about procedures and/or treatments to be done or not, it will convert GL into a reliable tool for daily clinical practice. Therefore it is not a confused and incomprehensible set of rules imposed by some scientific organizations.