Assessment of pretest risk for venous thromboembolic disease

Of the two most common types of venous thromboembolic disease (VTE) encount ered in the emergency department (ED), deep vein thrombosis (DVT) in the le gs often presents in an unambiguous way, and the diagnostic tests to identi fy the presence of a clot are noninvasive and in nearly all cases definitiv e.(13) Quite the opposite is true when one considers pulmonary embolism (PE ). This disease can present in a variety of ways, and more often than not t he emergency physician must consider an atypical presentation. Moreover, th e physical examination is often unhelpful, and ancillary laboratory tests a re less than conclusive.(1) Many patients need radiologic studies to help t o confirm the presence of the disease, but these studies also are not witho ut uncertainty. The physician's index of suspicion can be used to categoriz e the risk for the disease. This article evaluates how this level of physic ian suspicion-commonly referred to as the pretest risk-can be better unders tood and suggests a more uniform approach based on the best published data.