A frailty index is a common tool used in geriatric research to measure the overall health and functional status of older adults. It is typically calculated by assessing a variety of physical, cognitive, and psychological health indicators and assigning a score based on the number and severity of deficits present. The frailty index is used to identify older adults who are at risk for adverse health outcomes such as disability, hospitalization, and mortality. Researchers use the frailty index to study the causes and consequences of frailty, as well as to develop interventions to improve the health and quality of life of older adults.