The Cross-Cultural Neuropsychological Test Battery (CCNB): Effects of Age, Education, Ethnicity, and Cognitive Status on Performance

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1 1 The Cross-Cultural Neuropsychological Test Battery (CCNB): Effects of Age, Education, Ethnicity, and Cognitive Status on Performance Malcolm B. Dick, Ph.D. Institute for Brain Aging and Dementia University of California, Irvine Evelyn L. Teng, Ph.D. Department of Neurology, School of Medicine University of Southern California Daniel Kempler, Ph.D. Department of Otolaryngology, School of Medicine University of Southern California Deborah S. Davis, M.A. School of Social Ecology University of California, Irvine I. Maribel Taussig, Ph.D. School of Gerontology University of Southern California In: R. Ferraro (Ed.) Minority and cross-cultural aspects of neuropsychological Assessment (pp 15-39). Swets & Zeitlinger: Lisse, The Netherlands, 2002

2 2 Abstract The Cross-Cultural Neuropsychological Test Battery (CCNB) was developed in response to the growing need for a culturally fair method of assessing cognitive functioning in minority populations. The CCNB includes 11 tests, takes approximately 90 minutes to administer, and has been given to 336 healthy older adults and 90 demented patients from five ethnic groups (African-American, Caucasian, Chinese, Hispanic, and Vietnamese). The participants' age ranged from 54 to 99 years (M = 74.5, SD = 8.4) and they had from 0 to 22 years (M = 10.2, SD = 4.6) of education. While education contributed significantly to performance on most of the tests, age affected scores on measures of recent memory and psychomotor speed. Ethnicity and language affected scores on measures of attention, category fluency, and visualspatial functioning. As a whole, the demented patients scored significantly worse than their healthy peers on the entire CCNB. Tests of mental status and recent memory proved particularly useful in discriminating the two groups. Overall, the results demonstrated the effectiveness of the CCNB in identifying cognitive impairment in minority individuals and highlight the importance of considering education, age, and language when interpreting neuropsychological test findings.

3 3 The Cross-Cultural Neuropsychological Test Battery (CCNB): Effects of Age, Education, Ethnicity, and Cognitive Status on Performance The field of neuropsychology is being challenged by the increasing ethnic diversity and aging of the United States population. Currently, 12% of all Americans are over age 65 and 1 in 10 of these individuals is of minority background. By the year 2020, the 65 plus age group is expected to comprise 22% of the entire United States population, with a third of these seniors coming from diverse minority groups (U.S. Bureau of the Census & NIA, 1993). Despite the anticipated increase in the number of minority elders, relatively little work has been directed towards understanding the effects of age, culture, language, and education on neuropsychological test performance (Ardila, 1995; Gurland et al., 1992; Loewenstein et al., 1994). The lack of research on this issue is surprising as over a decade ago the National Institutes of Health, Consensus Development Conference, Statement on Diagnosing Dementias specifically noted the need for an "evaluation of results obtained with current neuropsychological instruments in populations that differ in age, education, ethnic composition, and social and cultural backgrounds" (NIH, 1987). As the number of older adults continues to grow, the incidence of chronic conditions associated with aging, such as Alzheimer's disease (AD), can be expected to increase in minority as well as nonminority populations. The prevalence of AD has been estimated as ranging from 1-3% in the age group, from 7-19% in those 75-84, and from % in those 85 and older (Evans et al., 1989; U.S. Congress Office of Technology Assessment, 1987). Although the number of neuropsychological studies of AD has increased substantially over the past decade, most of these investigations have included primarily English-speaking Caucasian participants. There are relatively few published studies examining neuropsychological functioning in either cognitively intact or demented minority populations. Apart from a handful of studies (Ganguli et al., 1991; Glosser et al., 1993), most of the existing research contrasts the performance of English-speaking Caucasians on specific neuropsychological tests with either African- American (e.g., Fillenbaum, Huber, & Taussig, 1997; Ripich, Carpenter, & Zioli, 1997; Ross, Lichtenberg, & Christensen, 1995) or Spanish-speaking (e.g., Jacobs et al., 1997; Pontón et al., 1996; Taussig,

4 4 Henderson, & Mack, 1992) individuals. To our knowledge, no published study has specifically compared the performance of elderly individuals from multiple ethnic groups on the same neuropsychological test battery. Neuropsychological assessment has retained its key role in the diagnosis of dementia despite improvements in neuroimaging techniques, such as magnetic resonance imaging (MRI) and single photon emission computerized tomography (SPECT). According to the NINCDS-ADRDA criteria, a clinical diagnosis of possible or probable Alzheimer's disease (AD) can be based on a patient's neuropsychological test profile after all other possible medical, psychiatric, and neurological explanations for the individual's symptoms have been ruled out (McKhann et al., 1984). As noted by Loewenstein and Rubert (1992), NINCDS-ADRDA established stringent neuropsychological criteria, with the cutoff for impairment as the 5th percentile or lower in each of eight cognitive domains (orientation, memory, language, perceptual skills, praxis, attention, problem-solving, and functional status). Since cognitive impairment is the primary and most essential criterion for the diagnosis and staging of dementia, it is essential to have reliable and valid neuropsychological tools that are applicable across diverse cultures. Identifying impairment, as defined by NINCDS-ADRDA, in individuals with different cultural, linguistic, and educational backgrounds is difficult without appropriate normative data. Clinicians may overestimate cognitive impairment in individuals with limited education, as these persons frequently score below the 5th percentile on neuropsychological tests (Ardilla, Rosselli, & Rosas, 1989; Ardila, Rosselli, & Puente, 1994; Taussig, Henderson, & Mack, 1992). For example, Pontón et al. (1996) found that nondemented Hispanic individuals with less than a 6th grade education scored up to two standard deviations below average when compared to persons with 16 years of schooling. These studies highlight the potential for misdiagnosis in the absence of appropriate tests or adequate normative data. In the absence of adequate norms, what is normal for one group (e.g., Caucasians) may be misinterpreted as pathological for another group. Consequently, the authors directed their efforts at compiling a set of relatively culturally fair neuropsychological measures with sufficient norms to allow accurate assessment of cognitive abilities in persons from a variety of ethnic backgrounds.

5 5 Method Development of the Cross-Cultural Neuropsychological Test Battery (CCNB) In 1991, the Southern California Alzheimer's Disease Research Centers (ADRC) formed a multidisciplinary Language and Cultural Advisory Committee for the express purpose of addressing problems associated with diagnosing dementia in individuals from diverse educational, linguistic, and cultural backgrounds. Experts in dementia and cross-cultural research from several fields, including neuropsychology, linguistics, gerontology, and neurology, collaborated to develop a brief neuropsychological assessment battery with broad applicability across the various minority groups served by the ADRCs in the United States. The committee's goal was to compile a battery of tests that would accurately (1) characterize the primary manifestations of AD in minority individuals, (2) discriminate between cognitive changes associated with normal aging and those seen in dementia, and (3) measure the progression of cognitive impairment. Several general guidelines governed development of the battery. First, the goal of minimizing administration time was achieved by limiting the CCNB to 11 instruments. Secondly, to facilitate comparisons between the wealth of existing data on English-speaking Caucasians and the performance of minority individuals, five well-established tests were included in the CCNB. Thirdly, the committee sought to reduce the effects of illiteracy or low education on performance, given evidence that even scores on a simple test involving continuous alternating finger movements show a high correlation with educational level (Rosselli et al., 1990). To achieve this goal, the committee employed several strategies, including using oral rather than printed instructions, requiring oral or nonverbal responses rather than written answers, and presenting pictorial rather than verbal stimulus information (Jensen, 1980) in the CCNB. Fourthly, as many minority families do not seek assistance until late in the course of a dementia (Elliott, Di Minno, Lam, & Tu, 1996), the committee included tests which can be performed by persons with moderate to severe cognitive impairment. Finally, to obtain valid data, the committee emphasized that the battery should be administered by a bilingual examiner in the patient's primary language rather than through a translator. Untrained translators may be unable to convey the nuances of cognition and

6 6 affect (Sabin, 1985), normalize the patient's thought processes in an attempt to make sense of disorganized statements, and unintentionally distort test data through omissions, substitutions, and condensation (Marcos, 1979). The committee identified tests for the CCNB through a multi-stage process, beginning with an extensive literature review. The limited number of instruments emerging from this review included Spanish (Escobar et al, 1986;, Bird et al., 1987; Taussig et al., 1992), Chinese (Katzman et al., 1988; Yu et al., 1989), and Japanese (Hasegawa, 1983) versions of the Mini-Mental State Examination (MMSE; Folstein, Folstein, & McHugh, 1975); the Escala de Inteligencia Wechsler para Adultos (EIWA; Green & Martinez, 1968) or Spanish version of the WAIS; the Hispanic Neuropsychological Battery (Valle, Hough, Cook-Gait, Lui, & Labovitiz, 1991); and French, Spanish, Chinese, and Japanese (Demers et al., 1994; Feldmam et al., 1997) translations of the test battery developed by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) (Morris et al., 1989). Each of these existing instruments has certain limitations. First, global measures of cognitive functioning, such as the MMSE, yield only a single score and provide little information about the separate abilities impaired in dementia. Secondly, although the EIWA has extensive and carefully collected population-based norms, these norms have limited applicability to Spanish-speaking older adults in the continental United States (López & Romero, 1988). The EIWA normative sample, collected in the mid- 1960s, is comprised of Puerto Ricans under age 65. Only 12% of Hispanic Americans, however, are of Puerto Rican heritage, while almost half are of Mexican background (U.S. Bureau of the Census, 1993). Thirdly, usefulness of the Hispanic Neuropsychological Battery is limited by the small normative sample of 42 non-demented and 30 demented individuals. Fourthly, although the CERAD neuropsychological test battery has been translated into multiple languages, normative data for non-caucasian individuals is very limited. In addition, the CERAD battery includes tests, such as the Word List Memory task that is of limited usefulness with illiterate individuals (Ganguli, et al., 1991), as well as, instruments such as the Boston Naming test which is affected by both cultural/linguistic (Fillenbaum, Huber, & Taussig, 1997; Ross et al., 1995; Taussig et al., 1992; Valle et al., 1991) and educational (Rosselli et al., 1990) variables.

7 7 While the instruments which existed at the time of the survey represented progress toward accurate neuropsychological assessment of minority individuals, the committee recognized that the approach of designing unique tests for every minority group would not only be too costly, but also hamper crosscultural comparisons. Given the handful of published instruments, the committee decided to survey 16 ADRC sites across the United States and California's nine Alzheimer's Disease Diagnostic and Treatment Centers (ADDTCs) as a means of identifying tests commonly used to assess dementia in English and non Englishspeaking populations. Of the centers contacted, only a few had tests for assessing minority individuals. Results of the survey, like the literature review, revealed the need for a battery of neuropsychological tests with true cross-cultural applicability. Consequently, the committee moved forward with the task of selecting and/or developing instruments for the CCNB based on the five governing principles described above. Initially, the committee selected appropriate instruments from the pool of tests generated by the literature review and survey. The five commonly used tests which did not violate the guidelines were Trail Making Test Part A, WAIS-R Digit Span and Block Design, and the Animal Naming and Figure Drawing portions of the CERAD battery (Morris et al., 1989). Approximately 50% of the survey respondents used Trail Making Test Part A, 56% used Block Design and Figure Drawing, 62% used Digit Span, and 62% used animal naming as a measure of category fluency. Other frequently used tests were excluded in the selection process. For example, the Boston Naming Test, was not included in the CCNB although 94% of the survey respondents used this instrument to assess confrontational naming in Englishspeaking individuals. While the five familiar tests made cross-cultural comparisons possible, these instruments did not cover the broader range of cognitive domains impaired in AD. To supplement these five tests, the committee developed five additional tests, including Body Part Naming, Auditory Comprehension, Read and Set Time, Modified Picture Completion, and the Common Objects Memory Test. Development of these tests involved (a) selecting and translating items, (b) adapting items as necessary for the five target

8 8 groups (African-American, Caucasian, Chinese, Hispanic, and Vietnamese), (c) pilot testing and (d) final adjustments. First, items for each of the tests were selected and translated with the assistance of experts from each of the ethnic groups. Test items were translated and back-translated using the procedures outlined by Taussig et al. (1992). This standard process in cross-cultural research (Brislin et al., 1973) involves translation from English into the target language by one expert in that language, back translation by multiple individuals blind to the original English version, and comparisons of the back translations to ensure consensus and reconcile differences. During this process, the experts helped identify any biases or language-related issues in the test items. For example, as noted by Teng (1996), there are no words for certain body parts (e.g., shin, instep) in the Chinese language. Consequently, only body parts for which names existed in all five languages were included in the Body Part Naming Test. Following the selection, translation, and adaptation process, the committee pilot tested the items on small samples of minority individuals. Based on this pilot testing, final adjustments were made to the instruments. Using the standard translation process (Taussig et al., 1992), the committee also translated the five well-established tests into Vietnamese and Chinese. Existing Spanish language translations were used for the five tests. More specifically, instructions for Block Design and Digit Span were taken from the EIWA (Green & Martinez, 1968) and those for Trail Making Part A and the CERAD Category Fluency and Figure Drawing tests from Taussig et al. (1992). In addition to the 10 measures of specific abilities, the committee included translated and adapted versions of the Cognitive Abilities Screening Instrument (CASI: Teng et al., 1994; Teng 1996) as a global measure of cognitive functioning in the CCNB. Measures of Neuropsychological Functioning

9 9 The CCNB taps six cognitive domains: recent memory, attention, language, reasoning ability, visual spatial skills, and psychomotor speed. The 11 tests comprising the CCNB are listed in Table 1, according to the cognitive domain being assessed. Insert Table 1 about here It should be noted that many of the tests measure several domains (e.g., Digit Span can be considered a measure of working memory as well as of attention). The five well-established tests in the CCNB were administered using standardized procedures, as described in the references. The five new tests and procedures for their administration are described in detail here. Mental Status. Overall cognitive functioning was evaluated with the CASI which taps 10 cognitive domains commonly assessed in dementia: attention, concentration, orientation, short-term memory, long-term memory, language ability, constructional praxis, verbal fluency, abstraction, and everyday problem-solving skills. In most of these domains, scores range from 0 to 10 points, with the total CASI score ranging from 0 to 100. Designed for cross-cultural application, the CASI is easier to adapt for a variety of cultural/language groups than many of the screening instruments currently used with English-speaking individuals (e.g., MMSE). Unlike these instruments, when direct translation of an item is inappropriate, the CASI provides a culturally fair alternative. For example, as the phrase "No ifs, ands, or buts" is meaningless to non-english speaking individuals, the CASI provides alternative versions of this item, using linguistically equivalent phrases from other languages. Recent Memory. The authors developed The Common Objects Memory Test (COMT) as a culture fair measure of recent memory specifically for the CCNB. In this test, the examinee is shown a set of ten 3x5" color photographs of common objects (e.g., chair, scissors, leaf) across three learning trials at the rate of one picture every two seconds. The pictures are presented in a standard but different presentation order during each trial. The examinee is asked to name the objects aloud as they are shown and try to remember them for a later recall test. A test of free recall is given immediately after each trial.

10 10 After the third trial, the examinee is engaged with a brief distracter task (i.e., CERAD Figure Drawing) for 3 to 5 minutes and then asked once again to recall the items. This test of delayed recall is immediately followed by a recognition test in which the 10 original objects are interspersed with 10 distracters. The examinee is asked to indicate with a simple "Yes" or "No" whether an object was seen previously. The distracter items are similar to the original objects in terms of frequency of use and absence of distinctive details. Long-term retention of the original objects is assessed after a 30-minute delay using tests of recall and recognition, with a different set of 10 distracters. Language. Three tests are used to assess language abilities: confrontational naming of body parts, auditory comprehension, and category fluency for animal names. In body part naming, the examinee is asked to name 10 body parts as they are pointed to or touched by the examiner. Body parts were selected as (a) all cultures and languages have specific names for parts of the human body (Anderson, 1978), (b) body parts provide a range of "difficulty" from common (e.g., hand) to less common (e.g., eyebrow, fingernail), (c) body part naming is relatively unaffected by education (Rosselli et al., 1990), and (d) this task does not require any additional materials (e.g., pictures, objects) since the examiner's own body parts constitute the stimuli. The Animal Naming test from the CERAD battery requires the examinee to name "all the animals you can think of in one minute." Examinees receive credit for naming general categories (e.g., dog, cat) as well as specific exemplars (e.g., poodle, leopard). Repeated responses are counted only once. Finally, auditory comprehension is assessed by asking the examinee to execute 10 verbal commands, which range from simple one-step actions (e.g., open your mouth) to complex 3-stage tasks (e.g., put the watch on the other side of the pencil and turn over the card). The authors determined complexity of the commands by counting the number of "information units" contained in each statement. Grammatical complexity was specifically not manipulated since grammatical relationships vary markedly from language to language. The sentences in the comprehension section were translated into the target languages without altering the number of critical information units. The score on this test refers to the total number of informational units correctly responded to and can range from 0 to 25 points.

11 11 Visual Spatial Skills. The CCNB includes three tests which measure visual spatial functioning. The first, WAIS-R Block Design, is administered using standard procedures. The second test, CERAD Figure Drawing, requires the examinee to copy four figures of increasing complexity (i.e., circle, foursided diamond, pair of intersecting rectangles, and necker cube). There are specific criteria for scoring each figure, with a maximum total score of 11 points. The third test, Read and Set Time, involves having the examinee (a) read time on three clocks, set at 3:00, 7:10, and 4:45, and (b) draw the hands of a clock at three different times (i.e., 9:00, 4:10, and 7:50). In the clock reading portion, the examinee receives one point each for the correct hour and the correct minute, for a maximum score of 6. In the clock setting portion, the examinee receives one point each for the correct positioning of the hour hand, the correct positioning of the minute hand, and the correct relative length of the two hands, for a maximum score of 9. Reasoning. To assess reasoning ability, the authors complied a set of 10 pictures which tap similar concepts to those measured by the Wechsler Picture Completion tests. The CCNB version includes line drawings of persons from various cultures involved in universal experiences, but with an important part missing (e.g., a bearded man looking in a hand-held mirror, with the reflection missing the beard). The examinee is asked to identify the missing part in each picture either verbally or by pointing. Items are scored as either 1 (correct) or 0 (incorrect). Attention. The WAIS-R Digit Span is included in the CCNB to measure attention and is administered using standard procedures. Psychomotor speed. Part A of the Trail Making Test is used to assess psychomotor speed and administered using standard procedures. Phase 1: Norming the CCNB The normative sample included 336 healthy older adults from five ethnic groups: African- American, Caucasian, Chinese, Hispanic, and Vietnamese. To ensure representativeness of the sample, efforts were made to recruit an equal number of participants in the five ethnic groups from three age (i.e., 60-67, 68-75, and > 76 years) and education (i.e., 0-8, 9-12, > 13 years) ranges. Participants were

12 12 recruited through senior centers, diagnostic centers, and the Los Angeles and Orange County chapters of the Alzheimer's Association as well as through public service announcements. Participants were reimbursed $20 for their involvement in this study. Almost all of the participants in the Vietnamese, Chinese, and Hispanic groups spoke only their native language at home and the majority did not read English. Of the 61 Vietnamese participants, 97% spoke only Vietnamese and 56% did not read English. Of the 71 Chinese participants, 98% spoke only Chinese and 82% did not read English. Finally, of the 80 Hispanic participants, 81% spoke only Spanish and 63% did not read English. Median number of years in the United States was 3 for Vietnamese participants, 9 for Chinese, and 25 for Hispanic. All of the participants were tested either at home or a local senior center by trained examiners. The examiners administered the entire test battery in one sitting and obtained demographic and medical information from each participant. More specifically, all participants were screened for the presence of major health problems, cognitive impairment, depression, and functional deficits. Participants who acknowledged a history of stroke, head injury, traumatic loss of consciousness, or psychiatric, speech, language, or memory problems on a health questionnaire were excluded. In addition, all participants had to be free of any physical disabilities (e.g., movement disorders, uncorrected hearing or vision problems) that could interfere with neuropsychological testing. To help rule out cognitive impairment, each participant was asked to have a family member complete (1) the Informant Questionnaire of Cognitive Decline in the Elderly (IQCODE) (Jorm & Jacomb, 1989; Jorm, Scott, Cullen & Mackinnon, 1991) and (2) the Activities of Daily Living Scale (ADL) (Lopez and Taussig, 1991). The IQCODE is a 26-item rating scale that assesses cognitive decline in older adults independent of premorbid ability. A knowledgeable informant, usually the spouse, is asked to rate the degree of change in an older adult's memory and intellectual functioning over the previous 10-year period. Recent studies (Fuh, et al., 1995; Jorm & Jacomb, 1989; Morales et al., 1995) have shown that the IQCODE accurately discriminates normal from cognitively impaired individuals in various ethnic groups and has little correlation with education. The 18-item ADL scale was used to

13 13 exclude individuals with behavioral impairments in areas such as personal care, housekeeping, and management of finances from this study. In a comparison of English- and Spanish-speaking older adults, Lopez and Taussig found that their instrument accurately distinguished cognitively impaired from unimpaired elders regardless of language/cultural background. Finally, the Center for Epidemiological Studies Depression Scale (CES-D) was administered to all potential participants. Individuals who scored over the cutoff of 16 for clinical depression were excluded from the study. Numerous studies have documented the validity and reliability of the CES-D in both community and clinical samples of Caucasians, Hispanics, and African-Americans (Roberts, 1980; 1981) as well as in Chinese (Ying, 1988) and other Asian-American groups (Kuo, 1984). Data Collection and Analysis A total of 14 examiners administered the battery to the 336 healthy participants. The 3 Chinese, 3 Vietnamese, and 4 Hispanic bilingual examiners administered the battery in each participant's primary language and dialect. One African-American and 3 Caucasian examiners administered the battery to the English-speaking participants. All of the examiners received hours of training in administration and scoring of the CCNB. All written responses and scores were reviewed by the authors for possible errors. Research assistants double entered individual item scores from all of the tests into a database under the supervision of the authors. Accuracy of data entry was maintained by having different research assistants review the data files and by checking outlying scores. Hierarchical linear regression equations were used to examine the influence of age, education, and ethnic background on test performance. Preliminary regression analyses included each of the three variables of interest, as well as, all possible interaction terms. No interaction terms, however, were found to be significant. Thus, the analyses were repeated entering only the main variables. Education was entered into the regression equations first, as preliminary analyses indicated that Education had the greatest effect on performance. Age was entered second and Ethnicity variables was added last. Results

14 14 Participants Across groups, the healthy participants had a mean age of 73.2 (+ 7.6) years and attended school for an average of 10.2 (+ 5.0) years. More detailed demographic information on each of the five ethnic groups is shown in Table 2. Insert Table 2 about here The groups differed significantly from one another on Age, F(4,331) = 6.2, p <.001, and Education, F(4, 331) = 7.6, p <.001. Tukey-HSD comparisons, evaluated at a Bonferroni adjusted.01 level of significance, revealed that the Caucasians were significantly older than participants in the other groups. In an effort to include enough data from low education Caucasians, the researchers ended up testing a greater number of older individuals, as they were more likely to have fewer years of schooling. Test Scores Mean and standard deviation scores for the 11 tests are shown in Table 3 for each of the five ethnic groups. Comprehensive norms for each of the CCNB tests according to age, education, and ethnicity are presented elsewhere (Dick, Teng, Kempler, Davis, & Taussig, manuscript in preparation; Kempler, Teng, Dick, Taussig, & Davis, 1998). Insert Table 3 about here The percentage of variance accounted for by Education, Age, and Ethnicity is reported separately for each test in Table 4. Insert Table 4 about here

15 15 Analyses revealed that level of education affected performance on almost all the tests and, on average, accounted for 15% of the variance in scores. Age was more important than education on the COMT and affected performance on recall but not recognition. Age also played a role in tests involving visual spatial functioning (i.e., Drawing, Block Design) and psychomotor speed (i.e., Trail Making Test, Form A). Overall, age accounted for 4% of the variance, while ethnicity accounted for 10%. Ethnicity affected performance primarily on tests of attention (i.e., Digit Span), verbal fluency (i.e., CERAD Animal Naming), and visual spatial functioning (i.e., WAIS-R Block Design, CERAD Drawing, Read and Set Time). The Caucasians outperformed their African-American, Chinese, Hispanic, and Vietnamese peers on the Trail Making Test, CASI, and Modified Picture Completion test, but scored similarly to the other four groups on most of the remaining tests. The African-American participants had more difficulty than the other four groups on tests of drawing and visual-spatial constructional skills, while the Hispanics scored significantly lower than their African-American, Caucasians, Chinese, and Vietnamese peers on tests of category fluency and attention. Interestingly, there were no differences between the five ethnic groups on the COMT. All together, age, education, and ethnicity accounted for an average of 28% of the variance in test scores. As the CCNB is comprised of multiple tests assessing a limited number of constructs, factor analysis was used to determine if the tests loaded onto the expected constructs. The results of a factor analysis using a Varimax rotation procedure revealed a four-factor solution. The tests comprising these four factors are shown in Table 5. Insert Table 5 about here The five tests involving the processing of visual spatial information, namely Modified Picture Completion, Trail Making Part A, WAIS-R Block Design, CERAD Drawing, and Reading/Setting Time, all clustered closely together. Similarly, those tests assessing primarily language skills and/or requiring verbal responses (i.e., body part naming, auditory comprehension, category fluency for animal names, and

16 16 Digit Span) tended to group together. Interestingly, the two recognition tests formed a separate factor independent of the immediate and delayed recall portions of the COMT. Phase 2: Validation of the CCNB In Phase 2, the researchers administered the CCNB to neurologically impaired patients in each of the five ethnic groups with the goal of determining the how effective the battery would be at identifying cognitive impairment. A total of 117 cognitively impaired participants were recruited through the UCI and USC ADRCs. Twenty-seven individuals who scored at or near the floor on many of the CCNB tests were excluded from the validation sample. These individuals were all severely demented, with scores on the Clinical Dementia Rating (CDR) scale (Hughes et al., 1982) of 3 or higher. The final sample of 90 included 4 African-Americans, 20 English-speaking Caucasians, 18 Chinese, 39 Hispanic, and 9 Vietnamese individuals. Barriers to service use created by language, cultural, economic, and educational differences interfered with the authors achieving the original goal of administering the CCNB to an equal number of AD patients in each ethnic group. Eighty-four of the participants (93%) met the NINCDS-ADRDA diagnostic criteria for either probable or possible AD (McKhann et al., 1984). These participants evidenced mild-to-moderate dementia as indicated by CDR scores falling between 1.0 and 2.0. The remaining 6 individuals showed evidence of cognitive impairment on the clinical examination as well as the IQCODE and ADL measures, and scored 0.5 on the CDR (i.e., questionable or borderline dementia). Limiting the sample to less impaired individuals made it possible to focus on determining the sensitivity of the battery to mild dementia. Finally, none of the participants had a history of major psychiatric illness, chronic alcoholism, other neurological disorders, or any physical impairment which would interfere with performance of the tests. The presence of multi-infarct dementia was ruled out through the patient's medical history, including neuroimaging data (i.e., CAT and MRI scans) and a score of 4 or less on the Hachinski Ischemic Scale (Rosen, Terry, Fuld, Katzman, & Peck, 1980). The entire CCNB was administered to each cognitively impaired participant as part of the diagnostic evaluation. Although the 90 cognitively impaired participants were significantly older (M =

17 , SD = 9.3 years) than their 336 non-impaired peers (M = 73.2, SD = 7.6), t (423) = 2.7, p <.01, the two groups were similar in level of education. More specifically, the cognitively impaired participants and healthy controls had completed an average of 10.4 (SD = 4.1) and 10.1 (SD = 5.0) years of formal schooling, respectively. As might be expected, the mean score on the IQCODE was significantly larger, t (341) = 18.2, p <.001, in the cognitively impaired participants (M = 4.3, SD = 0.6) than in the healthy controls (M = 3.1, SD = 0.4). Results Both ANOVA and logistic regression procedures were used to analyze the data. Given the small number of cognitively impaired participants in some of the ethnic groups, it was not possible to compare test sores for healthy and impaired individuals in each of the minority groups separately. Rather the data from the cognitively impaired participants were considered as a whole in the analyses. A series of ANOVAs compared the performance of the 336 healthy controls and 90 cognitively impaired participants on each of the 11 tests in the battery. Given the significant difference in age between the two groups, age was included as a covariate in all of the analyses. Age, however, did not turn out to be a significant factor in any of the analyses. As shown in Table 6, the healthy controls scored significantly higher than their cognitively impaired peers on all 11 tests in the CCNB. As might be expected, the difference between the 3-5 minute and 30 minute recall tests was significant in the cognitively impaired participants, t (88) = 3.6, p <.01, but not in the normal controls, t.(332) = -0.4, p =.69. While the cognitively impaired participants scored significantly below their healthy peers on both of the COMT recognition tests, the difference in performance at 5 and 30 minutes was not significant for either group. Insert Table 6 about here

18 18 Although the performance of the cognitively impaired and healthy participants differed on all 11 instruments in the CCNB, the results suggest some of the tests may be more useful than others at discriminating between these two groups. Table 7 reports the percentage of cognitively impaired and healthy older adults scoring in the impaired range on each of the 11 tests. Scores falling at or below the 5th percentile (i.e., two standard deviations below the mean, corrected for age, education, and ethnicity) are considered outside of the normal range. Clearly, the majority of healthy older adults in each of the five ethnic groups scored above the cutoff separating normal from impaired levels of performance. In contrast, many of the cognitively impaired participants scored below the cutoff, with the highest percentage showing deficits on tests of mental status (i.e., CASI) and recent memory (i.e., COMT). Insert Table 7 about here Using the results of the earlier factor analysis, composite scores were calculated for each of the four factors by summing scores on the individual tests. These composite scores were then entered into a logistic regression equation with the CASI total score and CASI-derived MMSE score (CASI-MMSE). The Recall factor, with an Odds Ratio (OR) of.80 and 95% Confidence Interval (CI) of.72 to.89, (p <.001), and CASI-MMSE (OR =.80, 95% CI = , p <.01) produced the best overall model based on the Hosmer and Lemeshow Goodness of Fit test (1989) with a Chi-Square of 8.80, p =.36, and 8 degrees of freedom. Although the complete CCNB can be administered to a cognitively impaired individual in about an hour-and-a-half, some clinicians may choose to use a shorter, less time consuming version of the battery. Logistic regression was used to identify the tests that most effectively differentiated healthy from cognitively impaired individuals. Measures that best separated the two groups included the 30-minute recall, 5-minute recognition, CASI-MMSE, WAIS-R Block Design, and Auditory Comprehension tests. The 30-minute recall was the most important of the tests (OR =.76, 95% CI = , p <.001), followed by the CASI-MMSE (OR =.89, 95% CI = , p <.005), WAIS-R Block Design (OR =

19 19.92, 95% CI = , p <.01), and 5-minute recognition (OR =.73, 95% CI = , p <.05). Together these four tests created a good fit to the model based on the Hosmer and Lemeshow test with a Chi-Square of 7.76, p =.45, and 18 degrees of freedom. Of the four minority groups, only the Hispanic was large enough to warrant separate analyses. When compared with the 80 Spanish-speaking healthy controls, the 39 Hispanic patients were highly similar in age and education, but differed significantly on almost all of the tests comprising the CCNB. As shown in Table 8, the Hispanic patients performed significantly worse than their healthy peers on all of the CCNB tests except Body Part Naming, WAIS-R Digit Span, and Part A of the Trail Making Tests. Insert Table 8 about here A subsequent factor analysis using Varimax rotation was performed on the data from the Hispanic sample and revealed a very similar model to that seen in the entire sample. When logistic regression was performed on the data from the Hispanic subsample, scores on the 30-minute recall (OR =.39, CI = , p <.001), 5-minute recognition (OR =.31, CI = , p <.05), and Auditory Comprehension (OR =.65, CI = , p <.05) best predicted AD. The model involving these three tests was a fairly good fit with a Chi-square of 1.59 and 8 degrees of freedom (p =.99). Discussion Through a comprehensive process the authors developed a set of relatively culture fair measures that assess the cognitive abilities commonly impaired in AD. When normative data from 336 healthy older adults in five ethnic groups were analyzed, the results indicated that education had the greatest effect on performance. Subsequently, the CCNB was administered to 90 cognitively impaired older adults from the same five ethnic groups. Analyses revealed that the CCNB can distinguish cognitively impaired from healthy older adults, with certain tests being more effective than others in differentiating these two groups.

20 20 Despite the best efforts of the authors to design a battery of culture fair tests, both education and ethnicity significantly affected performance on several of the instruments. Of these two factors, education had the greater influence, accounting, on average, for 15% of the variance in scores. The fact that less education was associated with lower test scores is not surprising as few tests of higher cognitive functioning are not influenced by education (Rosselli et al., 1990). Other investigators have also been unable to eliminate the impact of education on test scores (Ardila et al., 1989, 1994; Escobar et al., 1986; Ganguli et al., 1991; O'Connor, Politt, & Treasure, 1989; Taussig et al., 1992). Given the inescapable effects of education, researchers should follow the example of the present authors (Dick et al., manuscript in preparation; Kempler et al., 1998) and provide separate norms for different age, educational, and cultural groups as needed. While ethnicity impacted performance less than education on most tests, it accounted for as much or more of the variance than education on Animal Fluency, the CERAD Drawing task, and the WAIS-R Digit Span tests. Interpretation of these results should be based on (a) a clear differentiation between statistical group effects and the range of individual differences that occur within a group, and (b) an understanding of factors such as language that may contribute to ethnic differences in test performance. First, researchers should compare the size of group effects (i.e., average differences between groups) to the range of variations that occur within groups. In the CCNB normative sample, more variation occurred within the ethnic groups than between them. For any given test in the CCNB, the group effects were modest relative to the range of individual differences within the groups. As a great deal of overlap in individual performance existed between groups, it is inappropriate to interpret group effects as suggesting that everyone in a particular group (e.g., Caucasians) performed better on a given test than practically everyone from another group (e.g., Hispanics). Secondly, researchers should consider the influence that a variety of factors besides cognitive ability may have on test performance. For example, the finding that Hispanics obtained significantly lower scores on the WAIS-R Digit Span tests and the Animal Fluency task than the other groups could be interpreted in light of linguistic differences. Scores on both tests may have been related to the complexity

21 21 of a given language. For example, the Digit Span tests may have been more difficult for Hispanics than other participants as seven of the numbers from 1-9 are multisyllabic in Spanish. In comparison, all of the digits are monosyllabic in Chinese and Vietnamese, and only the number 7 has two syllables in English. Kempler et al. (1998) attributed the results of the Animal Fluency task to a comparable linguistic hypothesis. Interestingly, Hispanics, who scored the lowest of all the groups on this task, generated only multisyllabic words. In comparison, the Vietnamese scored the highest, with a majority of the words (80%) being monosyllabic. Word length may have reduced the scores of Hispanic participants as it is well known that multisyllabic terms take longer to articulate and retrieve from semantic memory (e.g., le Dorze, 1992), and are less successfully stored and manipulated in working memory (Baddeley, 1990; Caplan, Rochon, & Waters, 1992). Norms are useful to the extent that they accurately represent the characteristics of a particular population. To determine the representativeness of participants in this study, the authors compared their demographic characteristics to those of the 5,262 individuals assessed at California's nine ADDTCs (now known as Alzheimer's Research Centers of California) from 1986 to 1993 (Yeo, Gallagher-Thompson, & Lieberman, 1996). Ethnic identification data indicated that 76% of the patients were Caucasian, 10% were Hispanic, 8% were African-American, 4% were Asian/Pacific Islanders, and the remainder were from other groups. This distribution mirrored the ethnic breakdown of California's older adult population at that time, with the exception of the Asian/Pacific Islanders, who were underrepresented. Upon comparing age, education, and gender data for the four groups of ADDTC patients with that of the Caucasian, Hispanic, African-American, and Asian (i.e., Chinese and Vietnamese) participants in this study, the authors found a high level of similarity. In terms of age, Asians were the youngest in both the ADDTC population (M = 72.4) and the CCNB sample (M = 72.0), while Caucasians were the oldest, averaging 77 years in both the ADDTC population and our normative sample. Gender breakdown was also comparable in the ADDTC population and the CCNB sample, with the percentage of males falling at 33% and 36%, respectively. Finally, the mean number of years of schooling in the ADDTC population and CCNB sample were similar for the Hispanic (7.7 ADDTC vs. 8.3 CCNB), African-American (10.0

22 22 ADDTC vs CCNB), and Caucasian (12.7 ADDTC vs CCNB) groups. The CCNB Chinese and Vietnamese participants had attended school for an average of 11.2 and 8.6 years, respectively, while the more diverse ADDTC Asian patient group had a mean of 12.4 years of education. Overall, the comparison of CCNB participants to ADDTC patients indicates that the normative sample in this study was representative of the minority population in California. While our sample was representative, the ethnic groups were not equivalent in years of education. The authors purposely included participants whose educational levels varied greatly as equating education would have limited the generalizability of the results. To clarify, the average educational level for Caucasians was approximately 12th grade. If participants in the other four ethnic groups were matched at this educational level, the results would not be widely applicable, for example, to Hispanics, who on average completed 8 years of schooling. In addition, matching groups based on years of schooling can be relatively meaningless. Within any culture, persons who have attended school for the same number of years may differ in educational attainment due to factors (e.g., rural vs. urban, public vs. private schools) that affect the quality of education. Equating education across cultures in terms of years of schooling is even more problematic, as, for example, the curriculum covered in the first 6 years of schooling in Vietnam may vary greatly from that taught in the United States or mainland China. In conclusion, this multi-year project has produced a well-normed battery of cognitive tests for professionals, who are increasingly evaluating older individuals from a variety of ethnic groups for dementia. The CCNB, which is easy to administer and relatively short, can be used with several minority groups. The data reported here and elsewhere (Dick et al., manuscript in preparation; Kempler et al., 1998) delineate the range of normal functioning within five ethnic groups and report the relative influence of education, age, and ethnicity/language on performance. Further refinements, however, are necessary if the battery is to achieve widespread adoption by researchers and clinicians. In the current health care environment, patients are unlikely to receive neuropsychological testing due to the cost and time involved. Application of the CCNB in clinical settings may be limited by the 90-minute administration time. The results from the logical regression analyses suggest that certain of the tests can be eliminated,

23 23 thereby shortening the battery considerably while maintaining it's diagnostic accuracy. For instance, as scores on tests such as Body Part Naming, WAIS-R Digit Span, and Part A of the Trail Making Tests do not accurately distinguish healthy from cognitively impaired Hispanic elders, these tests would not need to be included in a diagnostic evaluation. In fact, the results of the logical regression analyses performed on all of the data suggest that a much shorter "core" battery could be developed which would include just 5 tests namely the CASI, COMT, CERAD Drawing, Auditory Comprehension, and WAIS-R Block Design. Hopefully, by shortening the battery to include only the most essential tests this will lead to greater utilization of the CCNB in applied settings. The authors encourage interested individuals to try out this battery and hope that pooling of data in the future will allow for updated and more refined norms.

24 24 Table 1 Summary of Tests Comprising the Cross-Cultural Neuropsychological Test Battery Cognitive Domain Mental Status Test Cognitive Abilities Screening Instrument (CASI) Recent Memory Common Objects Memory Test (COMT) * Language Body Part Naming * CERAD Category Fluency for Animal Names Auditory Comprehension * Visuospatial Read & Set Time * CERAD Drawing WAIS-R Block Design Attention WAIS-R Digit Span Reasoning Modified Picture Completion * Psychomotor Speed Trails Making Test, Part A * Denotes a new test developed by the authors

25 25 Table 2 Demographic Background of the Healthy Participants Age Education Group n M SD Range M SD Range % male African-American % Caucasian % Chinese % Hispanic % Vietnamese % Total %

26 26 Table 3 Mean and Standard Deviation Scores for Healthy Older Adults on the CCNB According to Ethnicity African- Caucasians Chinese Hispanic Vietnamese American CCNB Test M SD M SD M SD M SD M Mental Status CASI Recent Memory COMT Trial COMT Trial COMT Trial COMT 3-5 min. Recall COMT 30 min. Recall COMT 5 min. Recogn COMT 30 min. Recogn Language Body Part Naming Animal Fluency Aud. Comprehension Visual-Spatial Read & Set Test CERAD Drawing WAIS-R Block Design Attention Digit Span Fwd Digit Span Bkw Reasoning Mod. Pict. Completion Psychomotor Speed Trails Making, Part A