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Library 101

Using the library at FNU

Evidence Based Practice

In Lesson 1 we mentioned that information literacy is important to evidence based practice.  So what is evidence based practice (EBP)?  In their seminal article published in the British Medical Journal in 1996, Sackett, Rosenberg, Gray, Haynes, and Richardson define evidence based medicine (EBM) as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients” (1996, ¶ 2). While first introduced in the field of medicine, the concept of EBM has evolved to include other health care fields (Perry and Kronenfeld, 2005). Evidence based practice often refers to using the concepts first defined in EBM in health care. While EBM and EBP are often used interchangably, they are not necessarily exactly the same. For our purposes, we can think of evidence based practice as using evidence in clinical decision making (Gebb, Young, and Anderson, 2013).

Evidence based practice relies on following a series of steps to improve health care delivery and outcomes:

  1. Identify a clinical problem;
  2. Formulate a focused, answerable question;
  3. Locate relevant and appropriate resources;
  4. Search for information;
  5. Critically appraise the information; and
  6. Implement that information into clinical practice

As you can see, the concepts of information literacy are very important to steps three and four. The strategies we have discussed for locating and evaluating information will be put to use as you search for evidence.

Formulate a Question

After identifying a clinical problem, the next step is to form a focused, answerable question. So instead of asking,

"What are therapies for depression?"

you should ask,

"Does exercise reduce depressive symptoms in women?"


The PICO method was designed to help with this process. PICO stands for:

P = patient (or problem)

I = intervention

C = comparison

O = outcome

You can build your question by identifying each of the elements in your PICO statement. In the above example, our PICO statement may have looked like this:

P patient or problem 30 yr old female
I intervention exercise
C comparison (if necessary) antidepressants
O outcome symptom reduction, increased quality of life

Evidence Hierarchy

In order to search for evidence, you need to understand what is meant by that term. Evidence essenitally means knowledge which leads us to believe something is true. For example, evidence has to be shown to convict someone of a crime. In health care, we want to see evidence that a particular intervention or treatment will work. Importantly, we don't want to see just any evidence, we want to see the best evidence. For this reason, evidence is usually organized into a hierarchy, with the best evidence at the top and the least reliable evidence at the bottom.

Hover over each term below to see its definition.

Systematic Reviews
Overview of all primary studies on a topic
Meta-Analyses
Statistical studies that combine results of several independent studies and recalculate and reanalyze the data
Critical Appraisal
Summaries to answer specific clinical questions
Randomized Controlled Trials
Participants are randomly assigned to either a control group or a group that receives a specific intervention; other variables do not come into play
Cohort and Case-Controlled Studies
Both of these studies compare two groups of participants - one with a condition or having received an intervention, one without; a cohort study follows the groups over time, while a case control study looks at their histories
Consensus Statements
Guidelines from respected authorities (such as professional organizations)
Anecdotal Information
Information gained from personal experience -- the least reliable since it cannot be verified
(To see a visual representation, please use a larger device)

Searching for Evidence

Now that you know what the best evidence is, you can use advanced search strategies to help you find it. For example, limiters can be a great help when searching for evidence. Using the Publication Type limiter in EBSCOhost, you can limit your search to ONLY meta-analyses, for example.

The Publication Type limiter is found in the search options on the EBSCOhost search screen:

In an article record, there is a field to show the publication type. Using the limiter searches for your choice within that field.

Finding Evidence-Based Answers

References

Gebb, B.A., Young, Z., & Anderson, B.A. (2013). Evaluating and using the evidence. In B.A. Anderson & S. Stone (Eds.), Best practices in midwifery: Using the evidence to implement change. Springer Publishing.

Perry, G.J., & Kronenfeld, M.R. (2005). Evidence-based practice: A new paradigm brings new opportunities for health sciences librarians. Medical Reference Services Quarterly, 24(4), 1-16. https://doi.org/10.1300/j115v24n04_01

Sackett, D., Rosenberg, W., Gray, J., Haynes, R., & Richardson, W. (1996 Jan 13). Evidence-based medicine: what it is and what it isn't. BMJ: British Medical Journal, 312(7023), 71-72. https://doi.org/10.1136/bmj.312.7023.71