Original ArticlesIncidence and Risk Factors for Cognitive Impairment No Dementia and Mild Cognitive Impairment in African AmericansUnverzagt, Frederick W. PhD*; Ogunniyi, Adesola MBChB†; Taler, Vanessa PhD‡; Gao, Sujuan PhD§; Lane, Kathleen A. MS§; Baiyewu, Olusegun MBBS∥; Gureje, Oye MBBS, PhD∥; Smith-Gamble, Valerie MD*; Hake, Ann MD¶; Hendrie, Hugh C. MBChB*; Hall, Kathleen S. PhD* Author Information Departments of *Psychiatry ‡Radiology ¶Neurology §Medicine, Indiana University School of Medicine, Indianapolis Departments of †Neurology ∥Psychiatry, College of Medicine, University of Ibadan, Nigeria Supported by grants from the National Institute on Aging (R01 AG09956; P30 AG10133; R01 AG026096) and Alzheimer Association (IIRG-95-084). Reprints: Frederick W. Unverzagt, PhD, Department of Psychiatry, Indiana University School of Medicine, 1111 W. 10th Street, Suite PB 218A, Indianapolis, IN 46202 (e-mail: [email protected]). Received March 29, 2010 Accepted June 26, 2010 Alzheimer Disease & Associated Disorders: January–March 2011 - Volume 25 - Issue 1 - p 4-10 doi: 10.1097/WAD.0b013e3181f1c8b1 Buy Metrics Abstract The aim of this study was to estimate the age-specific incidence of cognitive impairment, no dementia and mild cognitive impairment (CIND/MCI) in a large, community-based sample of older African Americans in Indianapolis, IN. A longitudinal, prospective, 2-stage design was used with follow-up assessments 2 and 5 years after the baseline. A total of 1668 participants completed the 2-year follow-up and a total of 1255 participants completed the 5-year follow-up. The person-years method was used to calculate incidence rates. The age-standardized, annual incidence of CIND/MCI was 4.95% (CI=3.39-6.52) and the subtype of medically unexplained memory loss (single-domain and multidomain amnestic MCI) was 3.67% (CI 2.75-4.48). Rates increased with age (3.43% for participants aged 65 to 74 y, 6.44% from age 75 to 84 y, and 9.62% from age 85+ y), history of head injury [OR 2.37 (CI 1.31-4.29)], and history of depression [OR 2.22 (CI 1.16-4.25)] while increased years of schooling was protective [OR 0.91 (CI 0.85-0.97)]. Rates did not vary substantially by sex. Almost 1 in 20 elderly community-dwelling African Americans, and almost 1 in 10 of the oldest-old (85+ y) developed CIND/MCI each year in this cohort. Risk factors of age and education suggest exposures or mechanisms at both ends of the life span may be important variables in onset of CIND/MCI. © 2011 Lippincott Williams & Wilkins, Inc.