Venous thromboembolism (VTE) is a serious source of hospital morbidity and mortality. Chemoprophylaxis with heparin has been shown to reduce the occurrence of VTE, but it increases the risk of bleeding and it is uncomfortable to receive. For that reason, VTE prophylaxis should be reserved for patients at moderate to high risk of VTE and low risk of bleeding. However, identifying patients at low risk for VTE can be difficult, because most patients have at least one risk factor for VTE and there are no validated risk prediction tools for use in US hospitals. Instead, many hospitals have opted for a one-size-fits-all approach with near-universal prophylaxis, putting many patients at unnecessary risk of bleeding. However, to provide care that is truly patient-centered, US physicians face several challenges. First, there is no accepted risk calculator that they can use to estimate an individual patient's risk. Second, risk calculators are not readily available at the point of care. As a result, prophylaxis rates have remained stubbornly low in some institutions, while in others the rate of prophylaxis is high, but the rate of inappropriate prophylaxis is also high. This study uses a risk prediction tool developed at the Cleveland Clinic to assess an individual patient's risk of VTE. The tool is incorporated into the electronic health record in the form of a smart order set. In this randomized trial, we will assess the effects of the order set on physician behavior and patient outcomes . Examining the effectiveness of an electronic decision aid embedded in an EHR in routine clinical practice will test whether a smart order set can improve patient care by incorporating patient-specific factors into a complex decision process.