Evidence Based Practice

This guide is designed to provide information on what Evidence Based Practice is and how to find evidence.

What is Evidence Based Practice?

Evidence based practice (EBP) has many definitions. A widely cited definition is adapted from this definition of evidence based medicine (EBM):

The conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research. (Sackett et al., 1996, p. 71)

However, many have argued that this definition has flaws, and have offered alternatives. This one highlights the need for nurses to integrate the evidence with their own professional judgement with the patient's preferences:

An approach to decision making in which the clinician uses the best evidence available, in consultation with the patient, to decide upon the option which suits the patient best. (Muir Gray, 1997)


Muir Gray, J. A. (1997). Evidence-based health care: How to make health policy and management decisions. Churchill Livingstone.

Sackett, D., Rosenberg, W., Gray, J., Haynes, R., & Richardson, W. (1996). Evidence based medicine: What it is and what it isn't. British Medical Journal, 312(7023), 71-72. https://doi.org/10.1136/bmj.312.7023.71

Levels of evidence

Medical scientists and practitioners rank evidence according to its quality. When these types of evidence are ranked as levels, one on top of the other, the resulting image takes the form of a pyramid, because the higher the quality of evidence, the rarer it is, and the lower the quality of evidence, the more ubiquitous it is. The highest quality evidence (level 1 evidence) is the systematic review:

Hierarchy of evidence pyramid: top to bottom, systematic reviews, randomised control trials, cohort studies, case control studies, case series and reports, editorials and expert opinion

EBP Steps

The practice of Evidence-Based Practice is generally based on five fundamental steps.

Step 1: Formulating a well-built question

Step 2: Identifying articles and other evidence-based resources that answer the question (Finding the evidence)

Step 3: Critically appraising the evidence to assess its validity

Step 4: Applying the evidence

Step 5: Re-evaluating the application of evidence and areas for improvement