special subjects
Evidence Based Medicine and Clinical Guidelines
Introduction
Physicians have always felt that their decisions were based on evidence; thus, the current term “evidence-based medicine” is somewhat of a misnomer. However, for many clinicians, the “evidence” is often a vague combination of recollected strategies effective in previous patients, advice given by mentors and colleagues, and a general impression of “what is being done” based on random journal articles, abstracts, symposia, and advertisements. This kind of practice results in wide variations in strategies for diagnosing and managing similar conditions, even when strong evidence exists for favoring one particular strategy over another. Variations exist among different countries, different regions, different hospitals, and even within individual group practices. These variations have led to a call for a more systematic approach to identifying the most appropriate strategy for an individual patient; this approach is called evidence-based medicine (EBM). EBM is built on reviews of relevant medical literature and follows a discrete series of steps. 