It is a way to evaluate any type of information. The acronym stands for Currency, Relevance, Authority, Accuracy, and Purpose. This method was originally created by Sarah Blakeslee of UC-Chico's Meriam Library.
In the medical field, medical practitioners use peer-reviewed journals which go through an extensive process where the experts (peers) in the relevant field examine the author's work.
Are they a credible organization in the field?
Is there a product they are selling? A specific political view they are advocating?
Does the information have a date and are they asking for your information?
How To Find Reliable Health Information Online by the National Library of Medicine