This self-directed interactive learning page will introduce you to the concepts of evidence-based practice (EBP) research, the PICO method, and the application of PICO in developing search strategies for EBP projects. EBP is a problem-solving approach to health care that combines research evidence and medical knowledge with patient conditions and preferences (Melnyk et al., 2010, p.5). To find high-quality research evidence, one must prepare solid research questions before starting their research. PICO is a method used for developing good medical research questions in evidence-based practice.
Note. The 5 As of EBP. From "Nursing - Subject Guide" by Murdoch University, 2021, (https://libguides.murdoch.edu.au/nursing/ebp). Copyright 2021 by Murdoch University. CC BY-NC 4.0.
EBP includes the following process (Craig & Dowding, 2020):
1. Ask a question: converting information needs about medical problems into research questions
2. Access the evidence: searching for evidence to answer those questions
3. Appraise the evidence: evaluating the evidence for its truthfulness and usefulness
4. Apply the evidence: integrating findings with medical expertise, patient needs, and patient preferences to reach a decision and applying this decision
5. Audit or evaluate its effectiveness: evaluating performance and the outcome of the decision.
The PICO method can be applied in steps 1 and 2 to create good research questions and search strategies in an EBP project.
PICO is a method used to create a solid research question based on four elements including the patient or population (P) we want to study, the intervention (I) we intend to use, the comparison (C) of one intervention to another, and the outcome (O) we anticipate (Melnyk & Fineout-Overholt, 2010).
The PICO process begins with a medical case study or scenario. A research question is created based on this scenario and constructed in a way that can support the search for an answer. With a well-structured research question, researchers can prepare a solid search strategy to find high-quality evidence.
This table illustrates the meaning and implications of the four PICO elements (Godshall, 2015, p.26).
| Population |
What are some characteristics of the patient population? Population information usually includes: age; gender; ethnicity; educational status. Population information goes with a specific disease process or disorder (e.g., heart disease, diabetes, pancreatitis). |
| Intervention |
What is the recommended intervention? Information about intervention can be a treatment, procedure, diagnostic test, risks, or other factors that can influence the chance of getting better. |
| Comparison |
What do you want to compare the intervention to or against? Comparison information can include: no disease; placebo or no intervention; type of therapy given or not; prognostic factor B; absence of risk factor or characteristic (e.g., a non-smoker or non-drug user). |
| Outcome |
What is the outcome of the intervention? Outcome usually includes: risk of disease; accuracy of diagnosis; rate of occurrence of negative outcome (e.g., severe illness, development of more diseases, or even death). |
This section presents an example case study as well as how the PICO method is applied to develop a search strategy for an EBP project.
In a children’s unit at a local hospital, children are being readmitted for rotavirus, a stomach illness that results in severe diarrhea and belly pain. Children with this infection frequently present with severe loss of water in the body. The virus is transmitted through contact by the fecal-oral route. Each of the readmitted children was in the hospital a week earlier for another illness. You realise that these children must be acquiring the rotavirus infection in your hospital. You suspect handwashing may be a problem on your unit. You want to explore this occurrence through an EBP study. (Adapted from Godshall, 2015)
The research question for this case study is:
Does the incidence of readmission of paediatric patients <8 years of age with rotavirus decrease when correct hand hygiene is promoted to staff on the children’s unit, as compared to before the promotion?
The PICO framework in this case study is:
Population = inpatients younger than 8 years of age with rotavirus
Intervention = hand hygiene promotion for staff on the children's unit
Comparison = hand hygiene promotion in the workplace versus no promotion
Outcome = increase (or decrease) in the incidence of readmission of patients
Based on this PICO framework, you can develop a search strategy using keywords to describe each element of your PICO question.
First, consider what other words with a similar meaning (synonyms) or different spellings might be used.
For example, hand washing, hand hygiene, handwashing.
We use Boolean operators – AND, OR, NOT in uppercase – and some other tricks like phrases and truncation to combine our keywords. These are commands to the search engine.
For example, we can command the search engine to search all three variations of handwashing at the same time:
(handwash* OR “hand washing” OR “hand hygiene”)
The asterisk* will find all word endings or variations in spelling, such as handwash and handwashing.
Double quotation marks around two or more words will find the exact phrase.
OR in uppercase tells the search engine to find any of the words in brackets.
Brackets group together our synonyms, to tell the search engine which keywords to apply OR to.
We can combine several concepts together in a search string, like this:
Child* (handwash* OR “hand washing” OR “hand hygiene”) hospital* rotavirus
Many library databases have a search interface with multiple search rows which are ideal for combining several different concepts into one search. Use one concept per search row, like this:
Row 1: child*
Row 2: handwash* OR “hand washing” OR “hand hygiene”
Row 3: hospital*
Row 4: rotavirus
When there are separate search rows we don't need to use brackets. You might also use each search row for the different elements of your PICO question.
If you don’t find what you need, go back to your search box and change something. Add or remove a word, check your spelling, and so on.
Once a search strategy is created using the PICO method, you can start searching the library databases listed on Key Resources page in this guide. Once you have found relevant high-quality research, you will need to appraise or evaluate the information. You may come across a number of different types of research evidence. This is commonly known as the Levels of Evidence hierarchy.
Note. Hierarchy of evidence pyramid. From "Matching research design to clinical research questions", by Aslam, S., Georgiev, H., Mehta, K., and Kumar, A. 2012, Indian Journal of Sexually Transmitted Diseases and AIDS, 33, p. 49-53 (http://www.ijstd.org/text.asp?2012/33/1/49/93829). CC BY-NC-SA 3.0
To evaluate these different sources of information, you can follow this "Evaluate information sources" guide from the RMIT Learning Lab.
References
Aslam, S., Georgiev, H., Mehta, K., & Kumar, A. (2012). Matching research design to clinical research questions. Indian Journal of Sexually Transmitted Diseases and AIDS, 33, 49-53. Retrieved from: http://www.ijstd.org/text.asp?2012/33/1/49/93829
Craig, J. V., & Dowding, D. (2020). Evidence-based practice in nursing (Fourth edition.). Elsevier.
Godshall, M. (2015). Fast facts for evidence-based practice in nursing: implementing EBP in a nutshell (2nd ed.). Springer Publishing Company, LLC.
Melnyk, B. M., & Fineout-Overholt, E. (2019). Evidence-based practice in nursing & healthcare: a guide to best practice (Fourth edition). Wolters Kluwer.
Murdoch University (2021). Nursing - Subject Guide. https://libguides.murdoch.edu.au/nursing/ebp