Evidence based medicine is founded upon an ideal—that decisions about the care of individual patients should involve the “conscientious, explicit and judicious use of current best evidence.”1 Several publications are dedicated to evidence based medicine, and, at an international level, the Cochrane Collaboration has been formed to gather, analyse, and disseminate evidence derived from published research.2 Several practical approaches to evidence based medicine in clinical decision making have also been described. 3 4

Evidence based medicine, it is claimed, leads to improvements in clinicians' knowledge, reading habits, and computer literacy; provides a framework for teaching; enables junior team members to contribute to decisions; and allows better communication with patients and more effective use of resources.5 From an ethical perspective, the strongest arguments in support of evidence based medicine are that it allows the best evaluated methods of health care (and useless or harmful methods) to be identified and enables patients and doctors to make better informed decisions. 5 6

However, the presence of reliable evidence does not ensure that better decisions will be made. Claims that evidence based medicine offers an improved method of decision making are difficult to evaluate because current practice is so poorly defined. Medical decision making draws upon a broad spectrum of knowledge—including scientific evidence, personal experience, personal biases and values, economic and political considerations, and philosophical principles (such as concern for justice). It is not always clear how practitioners integrate these factors into a final decision, but it seems unlikely that medicine can ever be entirely free of value judgments.