Challenges in Cognitive Assessment of African Americans in Research on Alzheimer Disease

The goal of the Alzheimer’s Association is to change itself in ways that make it possible to reach and serve the diverse population of people with Alzheimer disease and their families more effectively. This is quite appropriate and timely given the current state of science and the future demographic changes that have been predicted. This paper will focus on cognitive functioning among older African Americans; however, many of these suggestions have relevance for other ethnic groups. Relatively little is known about cognitive functioning in aging African Americans. The few studies that have been done have typically focused on impaired individuals suffering from various forms of dementia. The differential impact of socioeconomic status on subject performance as well as the cultural biases in testing instruments suggests that assumptions of equality of patterns, continuity, and change observed in cognitive status between African Americans and Caucasians is as yet unfounded. Our understanding of cognitive status in older African Americans is limited by a multitude of factors. For example, Kenton (1991) identified limitations in the neurologic care of minorities. Much of the research on Alzheimer disease has been on samples from clinical populations who sought health care. According to Kenton (1991), minorities were much more likely to be without insurance or underinsured than whites, and thus not likely to be involved in clinical studies. In addition, to the lack of health insurance, cultural barriers to neurologic care are major limiting factors to the participation of African Americans in clinical studies (Whitfield, 2001). The implications of these difficulties can be seen in statistics for neurologic diseases and complications from the major chronic causes of mortality and morbidity (for example, hypertension—a major cause of strokes) that affect minorities, which are exacerbated by limited access to health care. An important question has emerged from the growing interest in ethnic diversity and aging: do models of cognitive functioning for whites replicate those of African Americans? Cross-ethnic studies of cognitive status consistency indicate that whites score higher on standardized tests of neuropsychologic functioning than do African Americans (e.g., Escobar et al., 1986; Fillenbaum et al., 1988). A frequently cited source of these differences is differences in mean levels of education (e.g., Albert et al., 1995) between the groups. One of the difficulties in comparing aging whites and African Americans on cognitive status tests is group differences in educational attainment levels. It is well documented that aging African Americans are more likely to have fewer years of formal education than aging Caucasians (Harper and Alexander, 1990). However, the differences in the quality of education received by aging African Americans as children is not inherent in discussions of racial differences in cognitive functioning in late life (Folstein et al., 1985). As a function of differential access to quality education, older whites may have obtained a higher quality of education than did most African Americans during childhood. Thus, whites and African Americans with a 12th grade education may possess different knowledge bases, skills, and learning strategies from which to draw upon: these are assessed via standardized measures of cognitive status. However, the skills that lead to differential outcomes or hindrances may well serve aging African Americans in tasks particular to their environments. Ethnic group differences associated with educational attainment underscore the need to first characterize within-race individual differences so as to better understand variability between groups. An important point to remember is that factors that account for between-group variability do not necessarily account for within-group variability (Whitfield and Baker, 1999). Thus, studies designed to understand within-race heterogeneity are important first steps in addressing diversity in cognitive status. Address correspondence and reprint requests to Dr. Keith E. Whitfield, Department of Biobehavioral Health, 315 E. HHD, The Pennsylvania State University, University Park, PA 16803, U.S.A. Alzheimer Disease and Associated Disorders Vol. 16, Suppl. 2, pp. S80–S81 © 2002 Lippincott Williams & Wilkins, Inc., Philadelphia