Subject Guides

Evidence Based Practice

A step by step guide to the evidence based practice process

What is evidence?

The second step in the EBP process is to ACQUIRE evidence. 

What is evidence? 

Evidence in the context of medical literature provides proof. It is created by experts or scholars in their area of research. The evidence produced in this research is transparent and reproducible. 

"Evidence-based research is the use of prior research in a systematic and transparent way to inform a new study so that it is answering questions that matter in a valid, efficient, and accessible manner."

Robinson, K. A., Brunnhuber, K., Ciliska, D., Juhl, C. B., Christensen, R., & Lund, H. (2021). Evidence-Based Research Series-Paper 1: What Evidence-Based Research is and why is it important? Journal of Clinical Epidemiology129, 151–157.

The Evidence Pyramid

The Evidence Hierarchy: What is the best evidence? 

  • Evidence hierarchies rank studies based upon the rigor (validity and reliability) of their research methods. The more rigorous the methodology, the less risk of bias, which leads to the highest quality of evidence. 
  • The study types toward the top of the pyramid have the most rigorous methodology and are therefore considered to provide the strongest evidence. 
  • Evidence is divided into 2 types: Synthesized and Primary
    • Synthesized evidence integrates evidence from multiple studies on the same topic. Many studies demonstrating similar results equals stronger evidence of a particular intervention.
    • Primary evidence are single studies. One study may have strong evidence if the methodology is strong, but not as strong as multiple studies demonstrating the same results. Evidence pyramid of synthesized and primary research

"Evidence Pyramid" by Dartmouth Biomedical Libraries is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Where to ACQUIRE evidence

Synthesized Evidence Sources: (Listed below are primary medical/clinical resources. Other databases may have synthesized evidence on your topic).

  • PubMed: use the field tag [sb] to limit your search to systematic reviews. systematic[sb]
  • Cochrane Library: a database of systematic reviews & clinical guidelines
  • TRIP database: high quality clinical research evidence
  • Epistemonikos: for evidence-based health care clinical decisions and health-policy questions

Primary Evidence Sources: Any database that contains primary research studies in the topic you are researching. 

Use the ASK link or contact a Health Science Librarian for additional assistance

Translate Your PICO into a Search Strategy Video

Where to Look for Evidence Video