Overall survival is a key endpoint in clinical research studies, particularly in the field of oncology. It refers to the length of time from either the diagnosis of a disease or the start of treatment until death from any cause. Overall survival is often used as a measure of the effectiveness of a particular treatment or intervention in prolonging the lives of patients. It is a critical endpoint in determining the success of new therapies in clinical trials and is a primary focus in evaluating the impact of different treatment strategies on patient outcomes. Overall survival rates can vary depending on the type of cancer or disease being studied, as well as the stage of the disease and other factors.