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Evidence-Based Practice
Evidence-based practice (EBP) has been defined by each field that employs it. There are common elements to the various definitions that include the judicious use of the best research evidence (i.e., highest quality, most current) in order to improve the health and safety of patients while reducing overall costs and variation in health outcomes. High quality best evidence is combined with professional expertise and the values, preferences, and expectations of the person under treatment or the population under consideration.
The emphases can be slightly different in different fields. While in clinical areas (Dentistry, Medicine, Nursing, and Pharmacy) the focus is on the patient, in Kinesiology, the focus is on the athlete and in Public Health, on a population.
In fields other than medicine, evidence-based practice focuses on the clinical experience and research evidence produced by nurses, allied health professionals, movement scientists, athletic trainers, and population health researchers.
You might find these additional definitions helpful:
- Professional expertise is the culmination of:
- the provider's experience treating and providing care or
- research and experience in population studies
- Values, preferences, and expectations are the ideas and beliefs about the body, healing, and return to activities of daily living/work/athletic participation. These ideas and beliefs can be confounded by comorbidities.
- Use of best research evidence includes using a systematic method to find, review, synthesize, and apply the highest quality research to a person's or population's issue(s).
There are several reasons EBP has become important in caring for patients, athletes, and for guiding decisions affecting populations.
- EBP provides a basis for decision making that reduces uncertainties introduced by any single study.
- It can reduce costs by focusing in on treatments with known outcomes.
- It adds new knowledge to the field under study so that researchers and clinicians are not continually asking the same questions about which treatments are effective and safe.
- EBP prioritizes the needs of the person in considering treatment.
What does evidence-based research look like? Here are some examples of questions researchers pursued to understand what the evidence shows and how to apply it to people. Click on the titles to be taken to the the articles. A snippet from the abstract is included below each title.
"Understanding Cannabis-Based Therapeutics in Sports Medicine"
"With increased use of cannabis-based products by the public for both recreational and medical use, sports medicine clinicians should be informed of historical context, current legal considerations, and existing evidence with regard to efficacy, safety, and risks in the athletic community."
"Bedrails and Falls in Nursing Homes: A Systematic Review"
"Some healthcare providers believe bedrails prevent falls, while others think they are ineffective and dangerous. A systematic review was conducted to address: 'For older adults living in nursing homes, does more or less bedrail use reduce the incidence of falls?'"
"The objective of this study was to review randomized controlled trials (RCTs), which included a wearable activity tracker in an intervention to promote physical activity among cardiac rehabilitation (CR) participants, and to conduct a meta-analysis for the outcomes of step counts and aerobic capacity (V˙o2max)."
Evidence-Based Practice Process
The process of evidence-based practice can be represented in various ways, differing somewhat by discipline, but it always begins with the person or population of interest: a patient, client, athlete, or a population, such as a group of adolescents in Detroit. The A's represent the steps that you take in the process, such as ASK a question, ACQUIRE information, APPRAISE information, APPLY the information, ASSESS the outcomes.
The EBP process begins and ends with the person or population.
- ASK a focused question. Is there a new intervention that is more effective than the one currently used? Which practice works well and what could be improved? Why should the intervention change?
- ACQUIRE the current evidence by conducting a literature search that will be guided by your research question.
- APPRAISE the literature: sort, read, and critique peer-reviewed literature.
- APPLY what you find in your decision-making process, remembering to integrate the evidence you've found with your expertise and the expressed preferences, values, expectations of the person or population.
- ASSESS the outcomes for the person or population by reviewing data and documenting your approach, including changes. Evaluate and summarize the outcome(s), then make evidence-based recommendations for day-to-day practice or policy.
Levels of Evidence
Pyramid-shaped models are often used to display the relative levels of evidence of research study designs. Several names are used for these models, including:
- Levels of evidence pyramid
- EBP pyramid
- Study design hierarchy
A research design's placement on an EBP pyramid provides information about its level of evidence. Meta analyses and systematic reviews are often listed at the top of EBP pyramids to indicate they are considered the highest levels of evidence. On the example EBP pyramid shown below, the primary study designs are randomized controlled trials, cohort studies, case control studies, and case series / case reports. Brief definitions of these study designs are available on the Study Designs tab of this box (above).
This level of evidence pyramid may be shared with you in sessions taught by informationists or librarians at the University of Michigan. Your textbooks or course materials may include other EBP pyramids or study design hierarchies. Other models may include additional study designs or information to help select high quality evidence to answer your clinical question.
Here are some additional examples:
- Levels of Evidence from Oxford Centre for Evidence-Based Medicine (March 2009)
- Hierarchy of Evidence from Duke University Medical Center Library & Archives
Primary vs. Secondary Literature
- Primary (unappraised) literature: Includes original individual studies, such as controlled trials, cohort studies, and case studies.
- Secondary (pre-appraised) literature: Analyzes and interprets groups of primary studies, including systematic reviews and meta-analyses.
Secondary Literature Study Designs
- Systematic Review: Brings together and distills the best evidence from the primary literature to answer a clinical question. Generally, this will pool the results of several RCTs or meta-analyses on the same clinical problem.
- Meta-analysis: A quantitative statistical analysis of several separate but similar experiments or studies in order to test the pooled data for statistical significance.
Key Primary Study Designs
- Randomized Controlled Study: A carefully planned experiment that studies the effect of therapy on real patients. Randomized controlled trials (RCTs) include methodologies (randomization and blinding) that reduce bias and that allow for comparison between an intervention group and a control group (no intervention). RCTs can provide sound evidence for cause and effect.
- Cohort Study: Follows patients who have a particular condition or receive a particular treatment over time, and compares them with another group who have not been affected by the condition or treatment being studied. Not as reliable as an RCT since the two groups might differ in ways other than the variable being studied.
- Case-Control Study: A study in which people who already have a condition are compared with those who do not. The researcher looks back over time to identify factors that might be associated with the condition. Often relies on medical data or patient recall and is less reliable than an RCT or cohort study because cause and effect is not necessarily established.
- Case Report: A report on the treatment of an individual patient. Because there is no control group for comparison, there is no statistical validity. A number of case reports is a Case Series.
Caveat
Level of evidence hierarchies assume the studies were conducted according to the best practices for the particular study design. If a study's methodology does not follow best practices, the level of evidence for that study will be lower. This means a well-conducted, rigorous cohort study could provide better quality evidence than a poorly conducted randomized controlled trial. This is one reason Appraise is an important step in the Evidence-Based Practice process.