Professor Baker serves as professor and associate chair of the Department of Health Policy and Management of the Bloomberg School of Public Health along with a joint appointment in Environmental Health Sciences. She also holds joint appointments in the Johns Hopkins School of Medicine in the Departments of Pediatrics and Emergency Medicine.

Professor Baker's many years in the Office of the Chief Medical Examiner of Maryland provided a fruitful link between forensic pathology and her specialty of injury epidemiology. Her early research attracted national attention and fostered the development of trauma centers because it showed the crucial importance of transporting seriously injured patients to hospitals that have the equipment and trained personnel needed to treat such patients, rather than merely to the nearest hospital, as was common in the 1960s and 1970s.

The fact that all states in the country now have child seatbelt laws is due in part to Professor Baker's discovery that children during the first year of life die in motor vehicles at rates far higher than any other age group prior to the teens. Her meticulous research findings helped convince state legislators throughout the nation to pass laws requiring the use of infant and child restraint.

One of her most important leadership roles was as vice chairman of the Committee on Trauma of the National Academy of Sciences. A major force in the development and writing of the landmark Injury in America, she helped carry to the press and to Congress the book's urgent message: that trauma is a sorely neglected problem of immense and costly dimensions. Congress responded to the committee's recommendations by establishing a locus for injury control in the Centers for Disease Control, funding centers of excellence and major research projects across the nation. Quite properly, the School of Public Health, and Professor Baker, was awarded one of these centers

In 1987 Professor Baker founded the Center for Injury Research and Policy at the Johns Hopkins School of Public Health, where a public health approach is used to identify injury risk factors and then to design, implement and evaluate prevention and rehabilitation programs. For example, the studies she conducted in the late 1990s and early 2000s showing the relationship between the risk of an accident and the number of people in cars driven by teenagers spurred the State of Maryland and other states across the nation to fashion tougher graduated licensing systems for teen drivers.

Other groundbreaking research by Professor Baker addressed such topics as the role of cigarettes in the house-fire deaths of nonsmokers; the relationship between alcohol and homicide; the use of drugs and medications in adolescent suicide; the prevention of injuries on Indian reservations; the etiology of falls in nursing homes; the epidemiology of fatal occupational injuries; and geographic variations in mortality.

An important focus of her efforts has been the training and encouragement of students and colleagues throughout the world. Not only at Johns Hopkins but also at the University of Minnesota and for the World Health Organization and the Wold Bank, she has instituted new injury-control courses and spurred students to address challenging prevention problems and research questions.

She has received numerous honors including the Prince Bernhard Medal for Distinguished Research, the Association for the Advancement of Automotive Medicine's Award of Merit, the American Trauma Society's Distinguished Achievement Award, Johns Hopkins' Distinguished Alumnus Award, and an honorary doctor of science degree from the University of North Carolina, Chapel Hill.