The most common definition of EBM is taken from David Sackett. It means integrating individual clinical expertise with the best available external clinical evidence from systematic research. EBM 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. The evidence, by itself, does not make a decision for you, but it can help support the patient care process. The full integration of these three components into clinical decisions enhances the opportunity for optimal clinical outcomes and quality of life. The practice of EBM is usually triggered by patient encounters which generate questions about the effects of therapy, the utility of diagnostic tests, the prognosis of diseases, or the etiology of disorders.