Overview of evidence-based practice

EBP involves the conscientious and judicious use of the most current and best available evidence along with the clinician’s expertise and consideration of the patient’s values and preferences to provide patient care.¹^,⁴^–⁶ Evidence-based care has been recognized by the Institute of Medicine as a critical component of safe, quality patient care.⁷ Despite the emphasis on evidence-based care and the millions of dollars spent in the development and conduct of research designed to improve patient care,⁸ it can take as long as 15 years for this newly discovered knowledge to be translated to clinical practice.⁹^–¹¹

Nursing has a long history of applying evidence to practice, dating back to the days of Florence Nightingale; however, little recognized progress was made in the formal EBP movement until the development of the Cochrane Collaboration, established by Archie Cochrane in the early 1970s in the United Kingdom. As this collaboration was evolving, a similar movement was evolving at the McMaster Medical School in Canada. Originally designated as evidence-based medicine, the concept has shifted over time to be referred to as evidence-based practice and is inclusive of all health care disciplines.¹^,⁴^,⁵

The process of evidence-based practice

There are many models to guide the process of EBP. Some of the best known models include the Iowa Model of EBP,¹²^,¹³ the Hopkins Model of EBP,¹⁴ the Melnyk/Fineout-Overholt model,¹ and the Rosswurm and Larrabee model.¹⁵^,¹⁶ Steps common to all EBP models include¹^,¹²^,¹⁴^,¹⁵:

Identify the problem or need for change

The first step in the EBP process is to identify the problem or need for change. Problem identification or “triggers” for change can arise from many sources and can be either knowledge or problem focused.¹² Problem-focused triggers typically arise from clinical problems or data. Perhaps performance improvement data shows an increase in surgical site infection, or clinical observation shows that female laparoscopic patients are having a higher incidence of postoperative nausea and vomiting (PONV) then other patients. Knowledge-focused triggers arise when a nurse or another member of the health care team gains new knowledge about current practice that may show improved patient outcomes. This knowledge may arise from reading journal articles or attending a conference.¹² After the problem is identified, it is important to form a work team that is inclusive of all involved stakeholders. Organizational support, to include commitment of all necessary resources, inclusive of employee time to work on the project, should also be obtained.¹²^,¹⁵

Refine the question

One of the most critical components of the EBP process is to form a focused, searchable, answerable clinical question. Successful completion of this task will literally drive the continued evolution of the project. A strong question typically addresses at least four major components (Box 9-1): the patient (or population), intervention, comparison, and outcome (PICO). A fifth component that may be included is time (PICOT).¹

BOX 9-1 PICO Components

P = Patient, population, or disease of interest

I = Intervention of interest

C = Comparison intervention of interest

O = Outcome of interest

From Melnyk BM, Fineout-Overholt E: Evidence-based practice in nursing and healthcare: a guide to best practice, ed 2, Philadelphia, 2011, Lippincott Williams & Wilkins.

The patient or population of interest may be further clarified by addressing the age, gender, ethnicity, or disorder (procedure or disease) in the question. Interventions can include elements such as a therapeutic intervention, a diagnostic test, exposure to disease, or a risk behavior. The comparison is the additional intervention that you are considering, such as another medication or nursing intervention, another diagnostic test, or frequently routine therapy or standard of care. The outcome of interest is the result that you are interested in improving or accomplishing. Often, one will evaluate multiple outcomes in an EBP project. The most essential component of an outcome is that it is measurable. Outcomes commonly measured in perianesthesia EBP projects include length of stay in a particular area, pain scores, incidence of PONV or PDNV, and patient satisfaction. Another important outcome measure that should be considered is cost of care.

When the PICO components have been defined, the next step is to organize them into a question. The most common EBP questions are focused on either an intervention, prognosis or prediction, diagnosis or diagnostic test, or etiology.¹ Templates for developing questions using identified PICO components are provided in Box 9-2. Box 9-3 provides an example of the process.

BOX 9-2 PICO Question Templates

Intervention: In P, what is the effect of I compared with C on O?

Prognosis and prediction: In P, how does I compared with C influence or predict O?

Diagnosis or diagnostic Test: In P, what is the accuracy of I compared with C in diagnosing O?

From Melnyk BM, Fineout-Overholt E: Evidence-based practice in nursing and healthcare: a guide to best practice, ed 2, Philadelphia, 2011, Lippincott Williams & Wilkins; Polit DF, Beck CT, editors: Nursing research: generating and assessing evidence for nursing practice, Philadelphia, 2008, Lippincott Willims & Wilkins.

BOX 9-3 Sample PICO Components and Question