Evidence Based Practice

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Evidence-Based Practice Definition

The most commonly cited is that EBP is “the conscientious, explicit, and judicious use of current best evidence in making decisions”(Sackett, Rosenberg, Gray, Haynes, & Richardson, 1996).

Sackett, D. L., Rosenberg, W. M., Gray, J. A., Haynes, R. B., & Richardson, W. S. (1996). Evidence based medicine: what it is and what it isn't. British Medical Journal, 312(7023), 71-72. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/8555924

History of EBP• Evidence-Based Practice has its roots in Evidence Based

Medicine (also referred to as Evidence –Based Health Care). • EBM was created in the 1980s and popularized in the early

1990s as a response to medical textbooks being unable to keep up with rapid changes in medicine and being frequently based on the interpretations of a small number of people in a respective field.

• At the same time, the medical literature in journals was being produced in record numbers, but at the same time was poorly organized.

EBP vs. Evidence-Based Medicine (EBM)

• EBM is primarily limited to the health care field and focuses on a specific patient or population. • Evidence Based Practice can be applied to

many fields. EBP is constantly being modified to best suit the subject to which it is being applied.• In all cases, you want to use the best evidence

to inform your practice.

Common questions in everyday practice:

• Which combination and sequence of treatments is most effective?

• Which patient symptoms predict better or worse outcomes?

• What is the experience of illness for a patient with this diagnosis?

• Which treatment is most effective and will produce the best patient outcome?

• If a diagnosis is left untreated, what might be the outcome?

The Evidence Based Practice Process

The EBP process is comprised of 5 steps:

1. Defining a question that needs to be answered.2. Acquiring the literature that will be analyzed.

(building and executing the search)3. Conducting a formal evaluation of the results, also

referred to as critical appraisal.4. Integrating the evaluated evidence into practice.5. Re-evaluating the process to assess its efficacy and

improve it in the future.

Defining the Question (PICO)P – Patient/Population/ProblemI – Intervention (drug, diagnostic test, etc.)C – Comparative Intervention (what, if anything are we

comparing it to)O – Outcome (what is our desired result)

• The PICO format is used to construct the clinical question in a specific manner

• Using PICO format helps you identify the most important parts of your question

Patient Population

• Consideration of the patient and population of interest

• Limit to age group, gender, or other group if possible

Intervention

• Exposure• Treatment• Patient perception• Diagnostic test

Comparison

• Could be true control, such as placebo or doing nothing

• Could be another treatment• Sometimes it is the usual standard of care

Outcome

• Outcome may be very specific• Outcome may be something that has a variety

of measures• Outcome may be inconclusive

PICO Example

In a 52 year old African American male with Type II diabetes, is metformin better than insulin at regulating blood sugar?

• Patient - 52 year old African American male• Problem - Type II diabetes• Intervention – metformin• Comparative Intervention – insulin• Outcome – Blood sugar levels

Pyramid of Evidence

Critical Appraisal involves carefully and systematically examining research to judge its validity, reliability, and the relevance to a particular context.

Things to Consider:1. Pyramid of Evidence2. Placement on the Pyramid does not equate to importance of the work3. Placement on the Pyramid does rank research by:

• Subject area• Type of research done within subject area• Committees / organizations who create guidelines• Complexity and Content of the work

Critical Appraisal

Types of Study Designs

Experimental – controlled study designObservational – experiential and anecdotalQuantitative – results defined by numbersQualitative – results defined by wordsSynthetic – reviews of multiple studies

Study designs are driven by the research question being asked, the population being studied, and the desired results of the study.

Identifying Bias

Part of critical appraisal is to identify potential biases in order to evaluate the validity of a study.

Common Types of Bias

Conflict of Interest Bias – researcher benefits from results or funding entity benefits from results

Wrong Sample Size – usually due to small sample sizePositive Results Bias – results are more likely to be published

because they are positiveCorrelation Bias – results appear to correlate but actually do not,

statisticallyMissing Clinical Data Bias – data can be erroneously or

intentionally omitted

Searching for the Best Evidence

• CINAHL – Nursing literature• Cochrane – Systematic Reviews• PubMed – Clinical Queries • National Guidelines Clearinghouse: http

://www.guideline.gov• Agency for Healthcare Research and Quality:

http://www.ahrq.gov/clinic/cpgsix.htm• National Institute of Nursing:

http://ninr.nih.gov/ninr

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