Library Guides: DOH205/206 Research Skills Guide: Evidence-Based Information

The steps in EBP

There are various ways of listing the steps in the Evidence-Based Practice process, but a common way has 5 main steps:

1	Expressing the problem as a clinical question (Ask the question)
2	Finding evidence-based resources that answer the question (Acquire the evidence)
3	Critically appraising the evidence to assess its validity (Appraise the evidence)
4	Applying the evidence (Apply the evidence)
5	Re-evaluating the evidence and its application (Re-evaluate the evidence)

Step 1. Ask the question: PICO

It can be useful to express your research topic as a clinical question. That way you can focus clearly on exactly what you need to know and work out the concepts you need to search for.

The clinical question should be:

relevant to the patient or the problem
formulated in such a way as to help with the search for an answer.

Using a question framework such as PICO can help you pinpoint your question, and from there your search strategy.

Each of the 4 letters identifies a key concept that will help you formulate your research question and/or your search strategy:

P	Patient / Population / Problem	Start with the patient, or group of patients, or problem
I	Intervention	What is the proposed intervention?
C	Comparison	What is the main alternative, to compare with the intervention? This might be: no intervention.
O	Outcome	What is the anticipated or hoped-for outcome?

More information: Question formulation techniques

Step 2. Acquire the evidence: Levels of evidence - Secondary and primary

There are two broad types of evidence: secondary and primary.

We list secondary first because in Evidence-Based Practice it is the higher level of evidence and will probably be what you seek first in answering a clinical or research question.

Secondary evidence (filtered, pre-appraised)

This is evidence assimilated, or put together, from a number of quality primary studies on a topic. It includes systematic reviews, meta-analyses, and evidence summaries.

This is sometimes referred to as filtered or pre-appraised evidence.

You can find it in specialised EBP sources such as The Cochrane Library (notably in the Cochrane Database of Systematic Reviews) and in health and medical databases such MEDLINE, PubMed and CINAHL Plus with Full Text. See Where to Search for Evidence, for details of where to search for secondary, filtered, pre-appraised evidence.

Primary evidence (unfiltered)

This body of evidence consists of original individual studies such as controlled trials, cohort studies, and case studies.

This is sometimes referred to as unfiltered evidence.

You can find primary studies in specialised EBP resources such as The Cochrane Library, notably in the Central Register of Controlled Trials, and in health and medical databases.

For more details on where to search for evidence please see our Evidence-Based Practice Guide

Step 3. Appraise the evidence: Introduction to critical appraisal

Once you have searched for information, you will need to critically appraise the studies you have found. This is a really important process because it ensures that studies with scientific flaws are disregarded, and the ones you include are relevant to your research question.

When evaluating primary research (research which hasn't been pre-appraised or filtered by others), you need to make sure the evidence you are including in your review is scientifically rigorous. The main questions to address are:

Is the study relevant to your question?
How scientifically did the researchers design the study, especially in their care to eliminate bias?
What do the results mean and are they statistically valid (not just due to chance)?

For a more detailed look at Critical Appraisal, head to the Systematic Review Guide - Critical Appraisal and the Evidence-Based Practice Guide - Appraise.