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Nursing 515/516 Theoretical Foundations for EBP/Implementing EBP: Evidence-Based Practice

This course guide is for students in Nursing 515 or 516. This guide has recommended databases, resources for EBP, and more.

Asking and Forming the Clinical Question

What is PICO (T)?

A clinical question needs to be directly relevant to the patient or problem at hand. It helps to phrase it in such a way as to get the best possible results from the evidence. PICO(T) makes this process easier. It is a mnemonic for categorizing the important parts of a well-built clinical question. It also helps to lay the foundation for your search strategy by identifying the key concepts that need to be in the article that can answer your question. 

Population/ Patient/ Problem – who are you researching?

Intervention – treatment you’re looking into. Examples include medications, exercise, therapies, diet

Comparison – standard treatment or alternate intervention

Outcome – must be measurable so it can be meaningfully compared

Time (optional) – what is your timeframe?

The clinical question helps you determine what to look for – what to include and what to exclude. Determine your question before beginning your search. Once you have your question, use it for search terms including similar or synonymous terms, for example immunization and vaccine. Remember to use main points for your search, not little ones - blood pressure, not vital signs. 

When you do your actual search, combine terms for different parts of your question, but not all four. It is recommended to look up the intervention or comparison, not both in your search, at least to start. Using too many search terms may limit your search unnecessarily. Aim for at least a couple pages of results. If you have over a thousand results, use limiters and additional search terms to narrow it down. Part of seeking clinical research is taking the articles you find in different searches and comparing them to each other.


The nursing library liaisons are not health sciences professionals so we cannot determine the accuracy or validity of PICO questions from nursing students. We recommend contacting your nursing faculty or graduate assistant feedback.  The Nursing Liaison Librarians can certainly help you with organizing your PICO questions as well as look for articles to address your formatted PICO question​.

Determining Levels of Evidence

Evidence-Based Practice is hierarchical and uses a rating system to determine the level of evidence. One of the more well-known systems is the one developed by Johns Hopkins. The level of evidence is directly influenced by the research study design, rigor and applicability to the population are significant factors. The stronger the evidence, the more confidence the results will lead to best practice. 

The Johns Hopkins EBP model uses 3 ratings for the level of scientific research evidence 

  • true experimental (level I)
  • quasi-experimental (level II)
  • nonexperimental (level III) 

The level determination is based on the research meeting the study design requirements  (Dang et al., 2021, p. 146-7).

You will use the Research Appraisal Tool (Appendix E) along with the Evidence Level and Quality Guide (Appendix D) to analyze and appraise research studies. (Tools linked below.)

Nonresearch evidence is covered in Levels IV and V.

Dang, D., Dearholt, S. L., Bissett, K., Ascenzi, J., & Whalen, M. (2021). Johns Hopkins evidence-based practice for nurses and healthcare professionals: Model and guidelines. Sigma Theta Tau.

Point-of-Care Tools