The health status of racial and ethnic minority groups in the U. S. has improved steadily over the last century. Despite such progress, disturbing disparities in health persist between majority and minority populations. In 1997, for example, average life expectancy at age 65 was 16.1 years for African Americans and 17.8 years for Caucasians. Demographic projections predict a substantial change in the racial and ethnic makeup of the older population, heightening the need to examine and reduce differences in health and life expectancy. Research to date has shown that health disparities are associated with a broad, complex, and interrelated array of factors. Disease risk, diagnosis, progression, response to treatment, caregiving, access to care, and overall quality of life each may be affected by variables such as race, ethnicity, gender, socioeconomic status, age, education, occupation, country of origin, and possibly other lifetime and lifestyle differences. The NIA is committed to addressing health disparities through its research programs. For example, Satellite Diagnostic and Treatment Centers, part of the national Alzheimer's Disease Centers (ADC) Program, have successfully recruited African Americans, Hispanics, Native Americans, and American Indian/Alaska Natives to AD prevention and treatment studies. Researchers on the NIA's Religious Orders Study have made a major effort to enroll African American members of the Catholic clergy; the nature of the study population enables the etiology and pathology of AD to be established among individuals with similar educations, occupations, socioeconomic status, and lifestyles. Five ADCs received funding in 2000 and 2001 specifically to encourage minority-related research, and in 2001 half of the NIA Director's Reserve funds, which encourage collaborative research projects, were allocated to minority-focused research. In addition, the NIA recently completed a year-long review of these issues and developed a comprehensive strategic plan to address health disparities in the older population.
Racial Differences in Cognitive Performance in Elders Disappear When Quality of Education Is Assessed. Racial comparisons on intelligence tests, neuropsychological tests, cognitive tests, and dementia batteries generally have shown that despite equating the groups on variables such as years of education and socioeconomic status, African Americans score lower on these measures than Caucasians. In this study, investigators reassessed the results of a standard neuropsychological test battery using an estimate of quality of education, the individual's score on the Reading Recognition subtest from the Wide Range Achievement Test (WRAT). After adjusting for this score, the majority of previously noted test score differences between African Americans and Caucasians became non-significant. This finding indicates a factor that can account for ethnic group differences on cognitive tests, and suggests characteristics that can be incorporated into new cognitive tests and measures that are culturally fair.
More African-Americans Than Africans Get Alzheimer's Disease. Over a 5-year period, researchers followed 2,147 African-Americans in Indianapolis, Indiana, and 2,459 Yoruba in Ibadan, Nigeria, age 65 and older, to see if they developed dementia and AD. They used a screening instrument that they developed specifically for use in comparative epidemiological studies of dementia in culturally disparate non-literate and literate populations. All participants at both sites received the same examination, which included an interview, neuropsychological testing, examination by a physician, and laboratory and imaging studies, when deemed clinically appropriate. Great care was taken to ensure that diagnostic consistency was maintained within and between sites. The results indicated that in the African-American group, 3.24 percent per year developed dementia, including 2.52 percent per year who developed AD. In the African group, 1.35 percent per year developed dementia, including 1.15 percent per year who developed AD. The identification of populations in which the prevalence of AD is much lower or much higher than that in the United States may greatly facilitate our understanding of the disease's etiology.
Future Research Directions in Health Disparities
Resource Centers for Minority Aging Research (RCMARs). The NIA-supported Resource Centers for Minority Aging Research continue to represent one of the Institute's most visible and focused efforts to build the national research infrastructure for minority aging research. The six RCMARs maintain active involvement in activities addressing the original RCMAR mission of establishing a research mentoring mechanism in minority health, enhancing professional diversity in minority health research, evaluating/developing measurement tools tailored to minority populations, and developing strategies for recruiting and retaining minority research participants. The RCMAR program is scheduled for renewal in FY 2002. To increase the impact of research on the minority community, the second generation of RCMARs will have a stronger central theme at each Center, will further emphasize mentoring responsibilities, and will integrate their activities with those of other NIA-supported Center programs.