The process of evidence-based practice can be summarised into 5 distinct steps; Ask, Acquire, Appraise, Apply and Evaluate. It is often considered in the form of a cycle as this should be an ongoing process within your dietetic practice. We describe each of the steps in more detail on this page.
Step 1: Ask
You need to translate what you need to know into a focused, searchable and answerable question. This will help you to develop your search strategy - defining what to look for and where to look for the evidence.
A helpful approach to developing a research question is the PICO method:
|
P |
Population, Patient or Problem |
Who or What? |
|
I |
Intervention or Exposure of Interest |
How? |
|
C |
Comparison or Control |
What is the main alternative, if appropriate? |
|
O |
Outcome or Objective |
What are you trying to accomplish, measure or improve? |
Step 2: Acquire
After completing Step 1, you now need to find the best evidence to answer the question, this is done through a literature search.
Before doing so you should:
- Identify the keywords and terms that relate to your PICO question. It is important to consider variations in spelling.
- Consider your inclusion and exclusion criteria, this may include; publication year, language, accessibility, the relevance of the paper to your PICO question and research type.
Within this step, it is important to understand the different types of research and the varying level of evidence available, to support you in your search. We would recommend you follow a hierarchical approach to your search. However, it should be noted that whilst there are differences in the perceived quality of evidence based on their study design, some types of design are more appropriate depending on the question being asked.
You also need to consider where you will source your evidence from. This could include discovery systems, databases and individual journals.
You can find more support for this step in the PEN System 'Research Methods' Knowledge Pathway.
Step 3: Appraise
Once you have acquired the evidence relevant to your question, you need to appraise it.
Appraisal involves critically reviewing the evidence, and considering its strengths and weaknesses. This process focuses on assessing the evidence’s reliability, validity and importance.
You can get an initial indication of the quality of evidence simply by looking at the study design. As outlined in the Hierarchy of Evidence of Study Designs, there are research designs which are considered more reliable, and are impacted less by bias. However, the hierarchy should only be used as a general guide, it is necessary to review each study independently.
There are numerous resources including frameworks and checklists to support with critical appraisal, depending on the type of evidence you are appraising. Some key resources have been listed below:
Step 4: Apply
After Step 3, if you have found evidence which is valid, significant and relevant, you need to establish if this can be applied to your service user(s).
As outlined in the ‘What is Evidence Based Practice’ page. It is important that you do not consider the evidence in isolation. You need to take into account your clinical expertise and judgement, the service user(s) values, preferences and situation, the practice environment, and the risks and benefits.
Key questions to consider here include:
- Do the results apply to my service user(s) or group, are they comparable with the subjects in the study?
- Is the intervention feasible in this practice setting?
- What else do I need in order to apply this evidence?
- Do the potential benefits of the intervention outweigh any potential harm?
- What are the service user(s) views and preferences?
Step 5: Evaluate
This step involves evaluation of both the service user(s) outcomes from any implemented interventions, and also your own performance. This may well lead to a re-evaluation of the chosen intervention, and as such the cycle of evidence-based practice may start again.
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