According to Mosby's Dictionary of Medicine, Nursing and Health Professions (10th Edition, 2016):
Evidence-based practice is "the practice of health care in which the practitioner systematically finds, appraises, and uses the most current and valid research findings as the basis for clinical decisions".
In order to promote the principles, teaching and implementation of evidence-based practice, a consensus statement was agreed by delegates at the second International Conference of Evidence-Based Healthcare Teachers and Developers held in Sicily in September 2003. The group agreed that evidence-based practice (EBP) requires that decisions about healthcare are based on the best available, current, valid and relevant evidence. These decisions should be made by those receiving care, informed by the tacit and explicit knowledge of those providing care, within the context of available resources (Margaret Edwards, Chapter 24: Evidence-Based Practice in Key Concepts in Nursing, edited by Elizabeth Mason-Whitehead, 2012).
Evidence-based practice ranks the quality of evidence by levels as seen in the image to the right. As you move from Level VII at the bottom to Level I at the top, the quality of the evidence improves. This level of effectiveness rating scheme is based on the work of Ackley, B., Swan, B., Ladwig, G. & Tucker, S. (2008) in Evidence-Based Nursing Care Guidelines: Medical-Surgical Interventions.
Source: ACAP Libraries, © 2021.
Evidence-Based Research Questions
Your question needs to identify the key problem, what treatments/tests are you preparing for the patient, what alternative treatments (if any) are being considered, and what is the desired outcome to promote or avoid.
P = Problem: How do you describe a group of patients similar to yours? What are the most important characteristics of the patient? This may include the primary problem, disease, or co-existing conditions. Sometimes the gender, age or race of a patient might be relevant to the diagnosis or treatment of a disease.
I = Intervention: Which main intervention, prognostic factor, or exposure are you considering? What do you want to do for the patient? Prescribe a drug? Order a test? Order surgery? Or what factor may influence the prognosis of the patient - age, co-existing problems, or previous exposure?
C = Comparison: What is the main alternative to compare with the intervention? Are you trying to decide between two drugs, a drug and no medication or placebo, or two diagnostic tests? Your clinical question may not always have a specific comparison.
O = Outcome: What do you hope to accomplish, measure, improve or affect? What are you doing for the patient? Relieve or eliminate the symptoms? Reduce the adverse events? Improve function or test scores?