Cannon, sister of Walter Bradford Cannon, established medical social work as an accepted subspecialty of social work first at Massachusetts General Hospital, and eventually throughout the U.S. Her career was closely associated with the development of medical social work that combined the skills of the nurse, the social worker, the social investigator, and the psychologist. Cannon began training medical social workers at Mass General in 1912. In Social Work in Hospitals (1913), she claimed that the diagnostic casework of the social worker was as important for treatment as was the clinical diagnosis of the doctor. Digital facsimile from the Internet Archive at this link.