Predicting Medical Risks and Appreciating Uncertainty

As the preeminent Canadian physician Sir William Osler so eloquently put it, "Medicine is a science of uncertainty and an art of probability." Clinicians often forecast the benefits of specific courses of action when consulting with patients, yet the reliability of the underpinning evidence, inherent biases (conscious and unconscious), and the limitations of medical findings often lead to diagnostic and/or treatment errors. In this paper, the authors present a number of specific examples related to risk and uncertainty in the context of clinical decision making-some more than a little alarming-including extremely high incidences of misdiagnosis, reluctance on the part of medical professionals to abandon treatment regimens that are doing patients no good and may be causing harm, and systemic flaws in medical research methodology that can impede important new data from reaching practitioners. The article concludes by exploring ways medical practice could change to reduce health risks, uncertainty, and errors