Evidence-based medicine (EBM) was initially called “critical appraisal” to describe the application of basic rules of evidence as they evolve into application in daily practices. Evidence-based medicine is defined as an explicit and judicious use of current best evidence in making decisions about the care of individual patients. Evidence-based practice is defined based on 4 basic and important events, which include recognition of the patient’s problem and construction of a structured clinical question, thorough search of medical literature to retrieve the best available evidence to answer the question, critical appraisal of all available evidence, and integration of the evidence with all aspects and contexts of the clinical circumstances (Manchikanti, 2008).
In daily practice the need for valid information about diagnosis , prevention, intervention, prognosis and harm are growing .it is estimated that a clinician would need an answer for many questions and the answer for such questions should be based on solid research evidence rather than an opinion or past undocumented and untested experiences. However, in reality the answer to these questions for the same patient usually differ from one clinician to another even in the same situations as clinicians are used to base their decisions on subjective rather than objective standards (Elstein 2004).
The adoption of an evidence-based approach in medical practice will help clinicians adopt a lifelong learning process to stay up to date with the current literature, to overcome some of the limitations of the current medical practice and to rationalize their clinical decision-making process, also providing the "scientifically proven" current best diagnostic or treatment modality to their patients (Choudhry et al., 2005).
The Shift toward Evidence Based Practice
Evidence Based Practice (EBP) requires a shift from the traditional paradigm of clinical practice grounded in clinical experience, and pathophysiological rationale. In the EBP paradigm, clinical expertise is combined with integration of best scientific evidence, patient values and preferences, and the clinical circumstances (Susan, 2007).
Evidence Based Practice is a clinical decision-making approach critical to promote best patient outcomes and problem solving approach in which physicians seek solution for question that arise during their day to day clinical practice, EBP aims to apply evidence gained from the scientific method to certain parts of medical practice and to assess the quality of evidence relevant to the risks and benefits of treatments (Sackett et al., 2000).
Evidence Based Medicine involves two fundamental principles in clinical decision-making. First, the evidence is always interpreted together with the patient's values and preferences by weighing the benefits and risks, and the costs associated to the treatment compared to the alternatives. Second, the strength of the available evidence may be variable, constituting a hierarchy of evidence on the basis of the ability of the study to avoid systematic bias (Anttila, 2008).
Evidence Based Medicine is the integration of clinical expertise, patient values, and the best evidence into the decision making process for patient care. Clinical expertise refers to the clinician's cumulated experience, education and clinical skills. The patient brings to the encounter his or her own personal and unique concerns, expectations, and values. The best evidence is usually found in clinically relevant research that has been conducted using sound methodology (Sackett, 2002).
Steps of Evidence Based Medicine
According to Shaheen (2009), practicing EBM includes the following steps (5 as model) as shown in figure (1):
Assessment of the patient.
Asking clinical questions about the patient problem.
Acquiring the best available evidence that answers these questions.
Appraisal of evidence for its validity and usefulness.
Applying the results of the appraised evidence to the patient.
Fig. (1):Steps of Evidence based medicine (Shaheen, 2009).
Asking clinical question means to convert the patient's problem into clinical question in a specific format as shown in figure (2), (PICO) represents these particular components(Guidance of EFSA, 2010)where:
(P) is the patient problem or population of interest.
(I) is the intervention, independent variable or exposure.
(C) is the comparison intervention or exposure or reference intervention.
(O) is the outcome that patients look for (patient oriented outcome).
PICO question according to Moher and Tricco(2008) may be:
Therapy Question: Concerning the effectiveness of a treatment
Prognosis Question: Concerning outcome of a patient with a particular condition.
Diagnosis Question: Concerning the ability of a test to predict the likelihood of a disease.
Harm Question: Concerning the likelihood of a therapeutic intervention or exposure to cause harm.