Sources of information that inform evidence-based based practice are often ranked according to the rigor of the research that went into a scholarly publication. EBP experts and practitioners have different ways of describing this hierarchy of evidence. The hierarchy outlined below is based on the one outlined by Guyatt & Rennie (see the book on the right). For other descriptions of the ebp hierarchy, please see the box below this one.
The authors of the User's Guide to the Medical Literature outline a hierarchy of ebp sources as follows:
The basic premise behind the levels of evidence outlined by different experts are essentially the same. However, sometimes the terminology used to describe different sources of evidence can vary. Here are some additional websites that illustrate different ways of describing the levels of evidence: