A Battery of Tests for Assessing Cognitive Function in U.S. Chinese Older Adults—Findings From the PINE Study

With the rapid growth of the global aging population, especially the oldest old, cognitive impairment has become a pervasive public health issue. In the United States, population-based studies suggest that age-related cognitive impairment affects 17%–34% of community-dwelling older adults (1). The demographic shift will likely increase the prevalence of age-related cognitive impairment, place considerable demands on the U.S. health care system, and impose physical, psychological, and financial stress on patients, their caregivers, and family members (2). U.S. Chinese aging population is one of the fastest growing subpopulations of older adults in the country. The life expectancy of U.S. Chinese older adults is in the mid 80s (3). Given the prevalence of cognitive impairment increasing with age, we can expect a growing demand for geriatric care in Chinese Americans. However, the prevalence of cognitive impairment is relatively underresearched among U.S. Chinese older adults due to the lack of large scale population-based studies examining the prevalence of cognitive impairment and related clinical diagnosis including dementia or Alzheimer’s disease. Despite the data gap, research suggests that there is evidence to believe that Asian Americans should have the same rates or even higher than that of Caucasian older adults (4,5). In addition, some methodological challenges may have dampened our systematic assessment of cognitive function among Chinese older adults and to make sensible comparisons with other racial/ethnic populations. First, there was a lack of population-based studies which administered a cognitive battery of tests to measure cognitive function and change in different cognitive abilities among Chinese older adults. Cognitive impairment of older adults is not limited to memory, but reflects a host of different definitions, including impairments in language, visual, or spatial awareness, and attention. Multiple measures of each ability may be valuable in reporting different cognitive abilities. Second, since individual differences found at baseline are likely to become more pronounced over time, forming composite cognitive measures allows researchers to combine tests of various difficulty levels to reflect a wider range of cognitive performance (6,7). The use of standard score, or z score, has the statistical advantage of increasing power by reducing random variability present within different tests that accommodate a wide range of cognitive function performance, and has been widely reported in population-based epidemiological studies of U.S. older adults (6,8). Whereas recent studies have further identified the use of composite scores to better demonstrate performance characteristics in studies of cognitive impairment compared with other scoring methods (9), such reports remain scare among Chinese American older adults. Third, the paucity of data on cognitive impairment can largely be attributed to the absence of culturally and linguistically sensitive instruments to screen and diagnose cognitive impairment among this population (10). There existed a number of measure developed and adapted for use in different cultures and for multiple languages, such as the Cognitive Abilities Screening Instrument (11) or the Cross-Cultural Neuropsychological Battery (12). Despite these tests have been piloted among groups of Chinese Americans, the sample size was small, and the majority of items were taken from a few screening scale which may be limited to measure a wide range of cognitive performances. Apart from existing methodological challenges, culturally specific perceptions, beliefs, and negative affects relating to cognitive impairment further present challenges to engaging Chinese American older adults to research studies (13), leaving Chinese older adults underrepresented in clinical studies, especially studies of cognitive impairment (14). As a result, we have incomplete knowledge on the scope of cognitive impairment and the effect of sociodemographic characteristics on the cognitive function among community-dwelling U.S. Chinese older adults, which is critical in informing culturally sensitive prevention strategies in the aging population. To fill in the knowledge void, in the current study, we adapted a battery of five tests for use with Chinese American older adults. These tests, including the Chinese Mini-Mental State Exam (C-MMSE), East Boston Memory Test (EBMT)-Immediate Recall, EBMT-Delayed Recall, Digit Span Backwards assessment, and Symbol Digit Modalities Test, have been validated and widely used among English-speaking and Spanish-speaking older adults in the United States (6,15). The objectives of this report is to: (i) describe cognitive function in an older U.S. Chinese populations using five cognitive function tests, (ii) explore the sociodemographic and self-reported health correlates of cognitive function, and (iii) describe the effect of key sociodemographic variables including age, sex, education on cognitive function.