Evidence: What is it, where do we find it, and how do we use it?

The purpose of this paper is to review the history and rationale for evidence-based medicine (EBM). The development of EBM is briefly described, together with the pros and cons of evidence-based research, review techniques, and resources. The current status of EBM with regard to the treatment of overactive bladder (OAB) is also discussed. In short, EBM can be defined as the conscientious, explicit and judicious use of current best evidence to make decisions about the care of individual patients. The four main steps are: (1) formulate a clear question from a patient's problem, (2) search the literature for relevant clinical articles, (3) evaluate and critically appraise existing evidence for its validity and usefulness, and (4) implement useful findings in clinical practice. The power of the evidence-based approach can be enhanced by the development of techniques such as systematic review and meta-analysis. However, although EBM allows us to use current best evidence to make decisions about patient care, the evidence gained from systematic review and meta-analysis only applies to an "average patient" and is not readily adaptable to issues such as etiology, diagnosis and prognosis. (C) 2003 Published by Elsevier B.V.