OVERVIEW

Olmsted County, Minnesota, is one of the few places in the United States, or indeed the world, where one can conduct detailed studies of disease etiology and outcome in a defined geographic population. This unique capability results from the foresight of the early leaders at Mayo, who preserved the patients' complete and unified medical histories and provided an index to the diagnoses and procedures contained therein, as well as from the generous cooperation of the other medical care providers in the community, who have been willing to share their records on local residents. Equally important is the willingness of the residents of Olmsted County to contribute their own personal medical information to help better understand the natural history of disease.