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AlzRisk Cohort Detail

Cohort: Rochester Epidemiology Project
Risk Factors:

Introduction to the Cohort
The Rochester Epidemiology Project (REP) is based in Olmsted County, Minnesota, USA (population 106,470 in 1990), an area that is served by the Mayo Clinic, an internationally regarded tertiary care center, and one that is relatively isolated from urban centers other than the city of Rochester, where the Mayo Clinic is situated. The REP enables historical epidemiologic research in a system of linked community-based medical records. The Mayo Clinic, which provides care to many Olmsted County residents, began using a system of medical record keeping in 1910, and in 1966, this system was expanded to encompass non-Mayo health care providers serving county residents. As a result, nearly all county residents are represented in some form within the REP. In 1990, 10% of the Olmsted County population were aged 65 or older, and 51% were female.

Ethnicity Breakdown
In 1990, 96% of the Olmsted County population were white, many of northern European origin.

Diagnosis & Evaluation Methods
Diagnosis is based on medical record review, and diagnostic criteria have varied over time as standard criteria in the field have evolved. For example, Leibson et al (1997) and prior studies used criteria from the DSM III that were adapted for medical record review. In 2002, Edland et al used modified criteria from the DSM IV. In both approaches, investigators considered laboratory (for ruling out other causes), clinical and autopsy data in making AD diagnoses.

Edland SD, Rocca WA, Petersen RC, Cha RH, Kokmen E. Dementia and Alzheimer disease incidence rates do not vary by sex in Rochester, Minn. Arch Neurol. 2002 Oct;59(10):1589-93.

Leibson CL, Rocca WA, Hanson VA, Cha R, Kokmen E, O'Brien PC, Palumbo PJ. Risk of dementia among persons with diabetes mellitus: a population-based cohort study. Am J Epidemiol. 1997 Feb 15;145(4):301-8.

Melton LJ, 3rd. History of the Rochester Epidemiology Project. Mayo Clinic Proc, 1996; 71(3):266-74.