Evidence-Based Medicine: An Introduction

1. Introduction
The term evidence-based medicine (EBM) is increasingly used in the medical literature. In 1993, a search using the term yielded 6 citations,¹  whereas a similar search in April 2009 yielded 34,742 citations. The concepts of EBM were developed by clinical epidemiologists >20 yr ago.²  This burgeoning of EBM in human medicine has been extended to veterinary medicine, including equine medicine. An excellent presentation on how to apply EBM in practice was presented at last year’s (2008) annual convention of the AAEP.³  It seems that the terminology has at once generated considerable enthusiasm, confusion, and skepticism. The purpose of this presentation will be to review the underlying principles of EBM and to discuss some of the limitations of EBM for equine practice.

2. What Is EBM and Why Is It Important?
EBM has been described as “the integration of the best research evidence with our clinical expertise and our patient’s unique values and circumstances.”⁴  EBM refers not only to this laudable intention, but also to the methodology developed for accomplishing it. A fundamental principle of EBM is that, whenever possible, evidence for our clinical activities should be derived from well-designed studies of patients with spontaneous disease. The rationale for emphasizing patient-centered research is 2-fold. First, welldesigned studies of spontaneous disease have greater relevance to clinical practice than do experimentally induced disorders, because the latter are rarely good mimics of their natural counterparts. [...]