Anticoagulant is an effective treatment in prevention of strokes in patients with atrial fibrillations. But anticoagulant can also cause severe adverse effect, for example, hemorrhages. When two effective anticoagulants are compared, it is important to evaluate both the benefit, such as prevention of strokes, and risk, such as cause of hemorrhages. Since the impacts of strokes and hemorrhages on patients’ well beings are different, how to weight the two events in the benefit risk assessment becomes challenging clinically and statistically. The objective of this roundtable discussion is to share experiences in assessing benefit and risk involving events that need to be weighted differently, and to explore new statistical approaches for benefit and risk assessments. The key questions to be discussed are (1) What are the current approaches (2) Have the current approaches addressed the questions appropriately, what are the challenges? (3) What are the new approaches to be developed?