Wilkes University

Evidence-Based Practice and Information Mastery: Evidence Pyramid and Resources

A guide on the method of applying evidence-based practice to combat information overload and help the practitioner locate, evaluate and integrate the best information to improve the quality of care for the patient.

Levels of Evidence

In the medical sciences evidence is often ranked from the strongest to the weakest, with systematic reviews/meta-analyses considered to be at the highest level, or Level 1.  The rankings are based on the characteristics of research designs (methodology, validity, and applicability to patient care) and their ability to protect against bias. There is no one universally accepted hierarchy, but a ranking is often depicted using a pyramid.

Some Tools that Rate the Level of Evidence

These resources are only available to Wilkes staff, faculty and students:

Students 4 Best Evidence

This network for students interested in evidence-based healthcare  brings together relevant, useful resources about all aspects of EBH into a searchable, useable platform.

S4BE is divided up into two main areas, education and blogging. The education component includes both articles generated by S4BE contributors and signposts to outside content.

In addition to the educational aspect, S4BE has student bloggers who write about EBH. Their posts look at recent news in the health world or summarize new research. They also comment on problems and controversies in the health world, trying to find solutions.


EBM Pyramid and Resources

The evidence pyramid is a visual representation of grades of evidence.  For example, a systematic review of randomized controlled trials that show consistent results provides the highest quality evidence (i.e., the “gold standard”) and is at the top of the pyramid. Towards the base we find literature such as case reports or case series which are less likely to reliably predict outcomes. 

When making evidence-based decisions for patient care, it is essential to select the highest level research design available for the specific question of interest. But you should recognize that as you move up the pyramid, fewer studies are available; that is, high levels of evidence many not exist for all your clinical questions.  You many need to move down in the pyramid to other types of literature.

EBM Pyramid and EBM Page Generator, copyright 2006 Trustees of Dartmouth College and Yale University. All Rights Reserved.
Produced by Jan Glover, David Izzo, Karen Odato and Lei Wang.

Filtered Resources

Filtered resources appraise the quality of studies and often make recommendations for clinical practice.

Authors of a systematic review ask a specific clinical question, perform a comprehensive literature search, eliminate the poorly done studies and attempt to make practice recommendations based on the well-done studies. A meta-analysis is a systematic review that combines all the results of all the studies into a single statistical analysis of results.

Authors of critically-appraised topics evaluate and synthesize multiple research studies.

Authors of critically-appraised individual articles evaluate and synopsize individual research studies.


Unfiltered Resources

Evidence is not always available via filtered resources and searching the primary literature may be required.  It is possible to use specific search strategies in MEDLINE and other databases to achieve the highest possible level of evidence for your clinical question. 


Evidence-Based Medicine Websites andTutorials