Evidence Based Practice is a problem solving approach to the delivery of healthcare that integrates the best empirical evidence from well-designed research studies and patient care data, and combines it with patients expressed preferences and values, and professional expertise (including consideration of care setting and available resources).
Melnyk, B., Fineout-Overholt, E., Stillwell, S., & Williamson, K. (2009). Evidence-Based Practice: Step by Step: Igniting a Spirit of Inquiry. American Journal of Nursing. 109(11), 49-52. doi:10.1097/01.NAJ.0000363354.53883.58
Healthcare professionals conduct Evidence Based Research to support Evidence Based Practice because they want the best outcomes for their patients.
The Goal = best outcomes for the patient, highest quality of care
The Focus = finding evidence of the best methods, interventions and practices
The Evidence = found in the most current professional research literature and clinical practice guidelines
Start by formulating an answerable question to solve an information need related to professional practice. The question needs to be clear, focused and one that may be answered by published research studies.
The PICOT Question is a consistent, systematic way to easily identify the components of a clinical issue.
PICOT Elements
Who is the patient population we want to service or assist, or problem (P)?
Is there a proposed intervention or issue of interest (I)? What is the change or treatment under consideration?
Is there a comparison (C) intervention or issue of interest?*
What is desired outcome (O) of interest?
What is the time (T) it takes for intervention to achieve the outcome?**
*A comparison of the intervention or issue of interest may be “none” (i.e. no change in existing practice) or not pertinent in some questions.
**Time is not always required and is a challenging concept to search.
PICOT Question Template for an intervention or therapy question type:
In ________________________________________ (P)
how does __________________________________ (I)
compared with _____________________________ (C)
affect _____________________________________ (O)
within _____________________________________ (T)?
Watch: Evidence Based Research Video 1: Creating a PICOT Question
Read and Follow:
Next find evidence of the methods, interventions and practices used related to the PICOT question. The evidence will be found in research study articles published in current professional journals.
CINAHL and PubMed are great subject specific databases to use to find research studies in professional journals. The CINAHL database contains nursing and allied health literature and PubMed contains medical and life science literature so these two databases complement each others content and provide appropriate overlap for your research.
Effective Search Strategies:
Develop search statements that define your Population or Problem, Intervention or Issue of Interest, and Outcome of Interest
Use CINAHL Headings or MESH Headings to identify preferred terminology in the database
Use the Advanced Search with the AND connector to combine search concepts/terms
Use Limiters/Filters to map toward desired results
Watch: Evidence Based Research Video 2: Acquiring the Evidence with CINAHL
Read and Follow:
Next, consider what is our process for selecting high quality information to apply in practice?
As you review the research studies from your results - you want to ascertain:
The level of evidence plus internal validity are a proxy for quality and give clinicians confidence to apply evidence in practice.
Finally, consider external validity - how applicable and relevant is the information to the question at hand -- is it really relevant to your clinical issue and will you be able to apply it to professional practice?
Watch: Evidence Based Research Video 3: Appraise and Attribute the Evidence with PubMed
Read and Follow:
The Evidence Hierarchy Pyramid is used to graphically represent the quality of medical and health science research. The higher on the pyramid, the more comprehensive in scope is the research study, the more rigorous is the methodology conducted and the peer review.
Meta-Analysis: A meta-analysis is a review that combines the quantitative (numbers) results from different studies on a defined intervention in order to obtain a quantitative estimate of the overall effect of the particular intervention. A meta-analysis produces a stronger conclusion than can be provided by any individual study.
Systematic Review: A systematic review tries to identify, appraise, select and synthesize all RCTs (randomized control trials) relevant to a specific clinical question. Stringent guidelines are set in order to draw a conclusion about whether or not there is conclusive evidence about a specfic treatment or topic.
Randomized Control Trial: An RCT is a clinical trial in which the subjects are randomly distributed into groups that are either subjected to the experimental procedure (such as use of a certain rehabilitative treatment) or that serve as controls. It is the research design considered to provide the most reliable evidence for evaluating the effectiveness of an intervention. See Randomization
Randomization - used in RCTs: Randomization (or random allocation) is a method like tossing a coin to assign patients to treatment groups (the experimental treatment is given if the coin lands on "heads"; and a conventional, "control" or "placebo", treatment is given if the coin lands on "tails").
Cohort Study: A study designed to determine the relationship between a condition and a characteristic shared by some members of a group. The population selected is healthy at the beginning of the study. Some of the members of the group share a particular characteristic, such as cigarette smoking. The researcher follows the population group over a period of time, noting the rate at which a condition, such as lung cancer, occurs in the smokers and in the nonsmokers.
Retrospective or Case Control Study: A study where previously existing incidents of a medical condition are used in lieu of gathering new information. A group of patients with a particular disease or disorder, such as myocardial infarction, is compared with a control group of persons who have not had that medical problem. The two groups, matched for age, sex, and other personal data, are examined to determine which possible factor (e.g., cigarette smoking, coffee drinking) may account for the increased disease incidence in the case group.
Case Series: A report on a series of patients with an outcome of interest. No control group is involved.
Descriptive or Qualitative Study: A descriptive study is one in which information is collected without changing the environment (i.e. nothing is manipulated, no experiment is occurring). Sometimes these are referred to as correlational or observational studies. A descriptive study can provide information about the naturally occurring health status, behavior, attitudes or other characteristics of a particular group. Descriptive studies can involve a one-time interaction with groups of people (cross-sectional study) or a study might follow individuals over time (longitudinal study). These types of studies are often done before an experiment to know what specific things to manipulate and include in an experiment.
Pilot Study: The goal of pilot study is to assess the feasibility and acceptability of an approach/procedures on a small scale to see if it may work in a larger scale study. Thus, in a pilot study you are not answering the question “Does this intervention work?” Instead you are gathering information to help you answer “Can I do this?” (E.g. Can I recruit the target population, Will the participants do what they are asked, Can the treatments be delivered per protocol, etc.)
Practice Guidelines are concise statements designed to help clinicians and patients make decisions about appropriate healthcare for a specific clinical circumstance. Practice Guidelines are developed based on the research findings from meta-analyses, systematic reviews and RCTs and use clinical examples to demonstrate how to integrate these research findings into practice.
