In-hospital mortality refers to the rate at which patients die while receiving care in a hospital setting. This research area focuses on studying the factors that contribute to patient deaths during hospitalization, as well as identifying strategies to reduce mortality rates and improve patient outcomes. Researchers in this field may examine factors such as patient demographics, medical conditions, surgical procedures, quality of care, and hospital resources to understand the risks associated with in-hospital mortality and develop interventions to prevent it. The ultimate goal of research in this area is to improve the quality of care provided in hospitals and reduce the number of patient deaths that occur during hospital stays.