What is evidence-based medicine?

effects and costs of a medication when deciding a specific treatment. Also, a specific patient may not fit the criteria for enrollment of patients into a randomized controlled trial (RCT). For example, an RCT demonstrated that rifaximin, a nonabsorbable antibiotic, improved bloating in Lebanese patients [3]. Will bloating (and other gastrointestinal symptoms) improve if rifaximin is used in patients with irritable bowel syndrome (IBS) in the United States? If we assume that these results are applicable to patients with IBS in the United States, then is it worthwhile to use a treatment that may only produce a temporary relief of symptoms? What if the patient had a past history of Clostridium difficile colitis after a course of ciprofloxacin? Would the patient be willing to risk another case of C. difficile colitis? What if the patient does not have insurance and would have to pay $200 for this prescription? These questions are qualitative questions that require clinical judgments on the part of the patient and the physician [4]. Although the best evidence from an RCT [3] may identify an effective treatment for bloating, both physician judgment and patient preferences must also be used for effective clinical decision making. Thus, EBM and a reliance on best evidence is not intended to be “cookbook” medicine [2]. Nevertheless, EBM is a helpful tool for the quantitative aspect of clinical decision making, which arises from a systematic examination of study methodology and study results [2]. The medical literature is expanding at an exponential rate [5], and the time available for reading may be hurried and fragmented. Physicians need tools to build a framework for the rapid evaluation of the methodology and results of published studies, and EBM provides these tools (Tables 1.1 and 1.2). With these frameworks, physicians can rapidly identify well-designed studies that produce accurate and unbiased results and should be applied to patient care. Studies using improper methodology and biased results are quickly identified and ignored. What is evidence-based medicine?