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.