Skip to Main Content

Kraemer Family Library

Nursing Research

Evidence-Based Practice

This page goes over the basics of evidence-based practice (EBP).

You can use EBP to determine the best way to treat a patient. EBP uses clinical expertise, patient values and preferences, and best research evidence to determine the optimum treatment plans for patients. The next section on this page goes over the layers of the Pyramid of Evidence, which EBP uses to help determine the usefulness of a source. For other ways to evaluate sources, check out our Evaluating Articles page.

The Pyramid of Evidence

When discussing "evidence based practice" and articles that are "evidence based," there are several common models that put types of studies in a pyramid according to how much evidence they provide. For example a case study with one subject may not provide as much evidence as a randomized controlled trial with 400 participants. The amount of evidence is determined largely by the number of participants, but also the presence of a control group. Studies at the top of the pyramid are also supposed to have the least room for bias.

Here's the one pyramid model of evidence (CC-0): 

An EBP pyramid. From top to bottom, section one: secondary, pre-appraised, or filtered (clinical practice guidelines, meta-analysis, systematic review), section two: primary studies (randomized controlled trial - prospective, tests treatment, subsection 2.1: observational studies (cohort studies - prospective - exposed cohort is observed for outcome, case control studies - retrospective: subjects already of interest looking for risk factors), section 3: no design (case report or case series, narrative reviews, expert opinions, editorials) section 4: no humans involved (animal and laboratory studies).

 

A few things to keep in mind:

  • check the methods section of the article to see what type of article it is/where it fits on the pyramid
  • depending on your question, a case study or small qualitative study may be better than a large quantitative study
  • if a large sample lacks diversity or doesn't cover the population you're interested in, its results could still have limited applicability for your research
  • the pyramid here only represents one way of evaluating evidence. It is neither foolproof, nor absolute. Be sure to consider your assignment or research question requirements.