EBP is a problem-solving approach to clinical decision-making within a health care organization. It integrates the best available scientific evidence with the best available experiential (patient and practitioner) evidence. EBP considers internal and external influences on practice and encourages critical thinking in the judicious application of such evidence to the care of individual patients, a patient population, or a system (Newhouse, Dearholt, Poe, Pugh, & White, 2007).
Dearholt, Sandra L., and Dang, Deborah. Johns Hopkins Nursing Evidence-Based Practice : Models and Guidelines (2nd Edition).
Practice - Develop and refine your question and your team
Evidence - Search, appraise, summarize and synthesize internal and external sources of evidence.
Translation - Create and implement an action plan, evaluate outcomes, disseminate findings.
- Critical Appraisal Tools (Centre for Evidence-Based Medicine) Assess the quality of systematic reviews, diagnostic studies and randomized controlled studies.
- Oxford Centre for Evidence-Based Medicine: Levels of Evidence Descriptions of Levels of Evidence by clinical study category, and Grades of Recommendations
- Asking Focused Questions Use to help you build a PICO question.
- The Well-Built Clinical Question From the Introduction to Evidence Based Practice from Duke University Medical Center and Health Sciences Library At UNC, Chapel Hill.
|
Clinical Question |
Suggested Research Design(s) |
|
All Clinical Questions |
Systematic review, meta-analysis |
|
Therapy |
Randomized controlled trial (RCT), meta-analysis |
|
Etiology |
Randomized controlled trial (RCT), meta-analysis, cohort study |
|
Diagnosis |
Randomized controlled trial (RCT) |
|
Prevention |
Randomized controlled trial (RCT), meta-analysis |
|
Prognosis |
Cohort study Also: case-control study, case series |
|
Meaning |
Qualitative study |
|
Quality Improvement |
Randomized controlled trial (RCT) |
|
Cost |
Economic evaluation |
The "evidence pyramid" is often used to illustrate the levels of evidence in the literature. When beginning your search for evidence, begin at the highest possible tier.
Filtered information is "pre-appraised." This means that the content has been filtered to include studies and reviews that are of higher quality. Keep in mind that the amount of available literature and the number of problems covered gets smaller as you move up the pyramid.
Unfiltered information represents the original studies. These tiers may not contain studies of high quality and strong evidence, but they cover a much broader range of clinical problems and are much more available.
Nursing EBP: Levels of Evidence
Level I
Experimental study, randomized controlled trial (RCT)
Systematic review of RCTs, with or without meta-analysis
Level II
Quasi-experimental Study
Systematic review of a combination of RCTs and quasi-experimental, or quasi-experimental studies only, with or without meta-analysis.
Level III
Non-experimental study
Systematic review of a combination of RCTs, quasi-experimental and non-experimental, or non-experimental studies only, with or without meta-analysis.
Qualitative study or systematice review, with or without meta-analysis
Level IV
Opinion of respected authorities and/or nationally recognized expert committees/consensus panels based on scientific evidence.
Includes:
- Clinical practice guidelines
- Consensus panels
Level V
Based on experiential and non-research evidence.
Includes:
- Literature reviews
- Quality improvement, program or financial evaluation
- Case reports
- Opinion of nationally recognized expert(s) based on experiential evidence
From Johns Hopkins nursing evidence-based practice : Models and Guidelines
Dearholt, S., Dang, Deborah, & Sigma Theta Tau International. (2012). Johns Hopkins Nursing Evidence-based Practice : Models and Guidelines.
PICO is a mnemonic used to describe the four elements of a good clinical foreground question:
P = Population/Problem - How would I describe the problem or a group of patients similar to mine?
I = Intervention - What main intervention, prognostic factor or exposure am I considering?
C = Comparison - Is there an alternative to compare with the intervention?
O = Outcome - What do I hope to accomplish, measure, improve or affect?
When appraising research, keep the following three criteria in mind:
Quality
Trials that are randomised and double blind, to avoid selection and observer bias, and where we know what happened to most of the subjects in the trial.
Validity
Trials that mimic clinical practice, or could be used in clinical practice, and with outcomes that make sense. For instance, in chronic disorders we want long-term, not short-term trials. We are [also] ... interested in outcomes that are large, useful, and statistically very significant (p < 0.01, a 1 in 100 chance of being wrong).
Size
Trials (or collections of trials) that have large numbers of patients, to avoid being wrong because of the random play of chance. For instance, to be sure that a number needed to treat (NNT) of 2.5 is really between 2 and 3, we need results from about 500 patients. If that NNT is above 5, we need data from thousands of patients.
These are the criteria on which we should judge evidence. For it to be strong evidence, it has to fulfil the requirements of all three criteria."
Source: Critical Appraisal. Bandolier.