LibrarySkills@UCL for NHS staff

Identifying information (evidence) to inform your practice or research, requires search skills in order to:

• develop an effective search strategy, utilising standard search techniques;
• ensure the search strategy is suited to the purpose of your search;
• systematically carry out your search, on appropriate resources, such as bibliographic databases;
• ensure you retrieve a comprehensive, yet manageable set of results;
• enable you to review and refine your search.

The concept has evolved, and  as this graphic suggests, the views, values and expectations of the patient now play an important role in the process.  

Florida State University College of Medicine Evidence based Medicine Tutorial [online]. Available at: https://med.fsu.edu/medicalInformatics/ebmTutorial (Accessed 29 June 2022)

To give it wider application, and include other health care professions, EBM is also referred to as evidence-based practice, and is not static - it is an iterative process. A good way to think of it is as a cycle (see below). Any investigation of evidence is likely to lead to further questions, and practice should be considered on a regular basis, to see if improvements or refinements can be made. 

Erasmus, R T & Zemlin, A E (2009). Clinical audit in the laboratory. J Clin Pathol 2009; 62: 593-597.

This guide touches on three stages of the cycle:

• identify the question,
• search for evidence;
• critically appraise evidence.

Various frameworks may help you to identify the key concepts of your search topic, and later establish the search terms you will use to find relevant literature. Two such frameworks are PICO (for quantitative research, or research involving an intervention) and PEO (for qualitative research).

PICO divides your topic into four concepts:

P: the Patient / Population /Problem you are interested in.

I: the Intervention you are examining

C: a Comparison you might want to use

O: Outcomes you are hoping to achieve, or avoid

PEO can be useful for qualitative studies, where the intervention is an exposure (usually to something harmful or risky), and there is no comparator:

P: Population, Patient or Problem 

E: Exposure 

O: Outcome

Once you have identified your key concepts (either two or more), then you can develop this further, to express the concepts using the expected terminology in the literature; i.e. determine several alternaitve search terms for each concept (synonyms and different word endings).