presented in a checkbook ledger format. 7. Shopping with a Written List: Patients are asked ..... Lexington, MA: Heath. Kaplan, E., Goodglass, H.. & Weintraub, S.
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Neuropsychological and Prediction Among
Test Performance
of Functional
Spanish-Speaking
Speaking
Capacities and English-
Patients With Dementia
David A. Loewenstein,‘r2 Mark P. Rubert,’ Trinidad Argiielles,1~2r3 and Ranjan Duara,2p3r4
‘Departmentof Psychiatry, University of Miami School of Medicine, 2Wien Center for Alzheimer’s Disease and Memory Disorders, Mount Sinai, Medical 3Florida International
University,
Epidemiology,
and “Departments
University
of Miami
of Neurology,
Radiology
Center, and
School of Medicine
Neumpsychological measures have been widely used by clinicians to assist them in making judgments regarding a cognitively impaired patient’s abiliry to independently perform important activities of daily living. However; important questions have been raised concerning the degree to which neuropsychological instruments can predict a broad array of specific functional capacities required in the home environment. In the present study, we examined 127 English-speaking and 56 Spanish-speaking patients with Alzheimer’s disease (AD) and determined the extent to which various neuropsychological measures and demographic variables were predictive of per$ormance on functional measures administered within the clinical setting. Antong English-speaking AD patients, Block Design and Digit-Span of the WA&R, as well as tests of language were among the strongest predictors offinctional performance. For Spanish-speakers, Block Design, The Mini-Mental State Evaluation (MMSE) and Digit Span had the optimal predictive powe,: When stepwise regression was conducted on the entire sample of 183 subjects, ethnicity emerged as a statistically significant predictor variable on one of the seven functional tests (writing a check). Despite the predictive power of several of the
Address correspondence to: Dr. David A. Loewenstein, Director of Psychological Services and Neuropsychology Laboratories, Department of Psychiatry #204, University of Miami School of Medicine, Mount Sinai Medical Center, 4300 Alton Road, Miami Beach, FL 33140. 75
76
D. A. Loewenstein
et al.
neuropsychological measures for both groups, most of the variability in objective functional performance could not be explained in our regression models. As Q result, it would appear prudent to include functional measures as part of a comprehensive neuropsychological evaluation for dementia.
Neuropsychological assessment of the elderly patient remains important for many purposes including: (a) establishing the presence or absence of cognitive impairment; (b) determining the extent to which specific neuropsychological domains are affected; (c) diagnostic determination of specific brain impairment; (d) establishing a baseline for monitoring change or treatment effects; (e) assisting in remediation of specific disorders (La Rue, 1987, 1992; Loewenstein & Rubert, 1992). It is now recognized that cultural and language bias may influence these fundamental decision processes (Brislin, 1980; Loewenstein, Argtielles, Barker, & Duara, 1993; Lopez & Taussig, 1991; Valle, 1989). Functional assessment is also an important component when utilizing DSM III-R (American Psychiatric Association, 1987) or NlNCDS-ADRDA criteria to establish a dementia syndrome and in the diagnosis of such conditions as Alzheimer’s disease (AD) (McKhann et al., 1984). Clinicians are frequently asked to make judgments about a cognitively impaired patient’s ability to manage their finances, drive an automobile, live independently and their ability to manage guardianship of persons and property. In the past, the results of neuropsychological evaluation were typically used to assist with these important clinical determinations. However, neuropsychological measures based on models of human cognition or specific brain-behavior relationships may not be adequate for the prediction of functional capacities of cognitively impaired or demented individuals (Haut et al., 1991; Rubinstein, Schairer, Wieland, & Kane, 1984). Although a number of studies have demonstrated a positive relationship between measures of neuropsychological test performance and functional status, the strength of these associations have been generally found to be low to moderate (Chelune & Moehle, 1986; Hart & Hayden, 1986; Heaton & Pendelton, 1981; Williams, 1986). In one investigation, Teri, Larson, and Reifler (1988) found that instrumental activities of daily living of AD patients were related to the initiation/perseveration subtests of the Mattis Dementia Rating Scale (DRS: Coblentz et al., 1973). Functional performance, however, was not related to tests assessing construction, attention or conceptualization, and none of the cognitive subtests of the DRS was related to self-care skills. Disease severity appears to be a critical variable that impacts upon cognitive and functional measures. Most studies that have found neuropsychological-functional relationships have not accounted for the degree of overall cognitive impairment (Loewenstein & Rubert, 1992; Vitaliano, Breen, Albert, Russo, & Printz, 1984). The strength of association between neuropsychological and functional measures have generally been found to be especially weak in those investigations utilizing objective, behaviorally based functional measures, rather than relying
NeuropsychologicaWFunctional
Relationships in Two Cultural Groups
77
on caregiver and/or patient self-reports. Haut and associates (1991) found that neuropsychological variables were only modestly related to objective measures of functional status on the Direct Assessment of Functional Status (DAFS) scale (Loewenstein et al., 1989). In a more recent investigation, Loewenstein and colleagues (1992a) utilized stepwise regression equations to force a measure of global mental status, (the Folstein Mini-Mental State Evaluation: Folstein, Folstein, & McHugh, 1975), into the equation first, to determine whether measures of memory, reasoning, visuospatial skills, praxis, and language could predict actual functional performance beyond that provided by the MMSE alone. It was found that correlations between the MMSE and specific functional measures such as telling time, preparing a letter for mailing, counting currency, writing a check, balancing a checkbook, and shopping with a written list ranged from r = .07 to .62. Although, neuropsychological tests provided explained variance on functional measures well beyond that explained by the MMSE alone, no combination of the MMSE and the neuropsychological measures accounted for more than 50% of the explained variance on any functional scale. Thus, functional assessment can provide unique information for the neuropsychologist (Eisdorfer et al., 1992; Loewenstein & Rubert, 1992). Cultural and language bias against Spanish-speaking demented as well as nondemented patients (Geisinger, 1992; Loewenstein et al., 1992b, 1993; Lopez & Taussig, 1991; Olmedo, 1991; Rodriguez, 1992) may impact upon performance on neuropsychological and functional variables. To our knowledge there has been no research that has investigated the relationship between nemopsychological and functional performance among Spanish-speaking AD patients. Therefore, the present study attempted to determine the extent to which combinations of neuropsychological tests could predict specific functional skills and whether these relationships were similar or different for Spanish-speaking and non-Spanish-speaking AD patients.
METHODS Subjects
The present study evaluated a subset of a larger cohort of patients with complaints of memory loss who were evaluated by the Wien Center for Alzheimer’s Disease and Memory Disorders, an affiliated program of Mount Sinai Medical Center, Miami Beach and the University of Miami School of Medicine. Each patient received a comprehensive medical, neurological, psychiatric, and neuropsychological evaluation as well as laboratory tests that included hematology and blood chemistry profiles, electrocardiogram, electroencephalogram, and magnetic resonance scans of the head. Patients who completed neuropsychological and functional evaluations, and who met NINCDS-ADRDA criteria for probable or possible Alzheimer’s disease
78
D. A. L.oewenstein et al.
(McKhann et al., 1984) and for whom English or Spanish was their primary language were included in the present study. This resulted in two groups of patients: 127 patients for whom English was their primary language (35 males and 92 females; mean age = 77.29 & 6.6 years) and 56 patients who spoke Spanish as their primary language and were primarily of Cuban descent (25 males and 31 females mean age = 73.00 + 5.8 years). Procedures Each patient received a comprehensive battery of neuropsychological measures administered by a psychometrically trained examiner who had been trained by two of the principal investigators (D.L. and T.A.) for a period of 4 to 6 weeks. For Spanish-speaking adults, all neuropsychological and functional tests were carefully back-translated using the fundamental methodology adopted from (Brislin, 1970, 1980). A bilingual examiner then administered these tests in a standardized manner. Translation of neuropsychological andfunctional test batteries. In our translation, we went beyond mere back-translation and included pretest and committee translations. Back-translation is a three-step process through which material is produced in a particular language and subsequently translated into another language by a bilingual researcher. This material is then translated back into English by a separate bilingual researcher. Pretest translation is the procedure by which the material that has been back-translated has extensively been pilot tested with a subject group similar to the intended population after it has been back-translated. This is a means of cross-validating the instruments. Committee translation is a procedure through which the translations are done by a team of bilingual personnel as a checks and balances method. Instructions with different Spanish-speaking cohorts were used to make the Spanish version as free as possible of idioms, so a final version was as linguistically neutral as possible. Besides consultation with translators’ dictionaries and books in Spanish grammar the material evidenced high interrater agreement in the administration and scoring of Spanish-translated tests utilizing a modification of Brislin’s method (Brislin, 1970, 1980). Unfortunately, we could not completely translate the entire English test in a literal fashion and still render an entirely accurate Spanish version. As such, we had to establish a range within there could be several acceptable responses. For example, the word “harmonica,” as a response on a confrontation naming test has several acceptable responses in Spanish. In Castellan Spanish, this is “armonica” or “ harmonica”; however, Cuban individuals also learn “filarmonica” in school as a variant. This variant would be considered a regionalism in Castellan Spanish, because a regionalism could be a variant of the word that would be a variant of the word used in some countryside settings by uneducated individuals, or by a specific subculture, instead of the general popula-
Neuropsychologicalnctional
Relationships in Two Cultural Groups
79
tion. However, within the Cuban community such a variant actually reflects common usage. For the interested reader, a more thorough description of our method of translation and the checks and balances, utilized to ensure against Anglicisms and other translator biases, which are especially vital when assessing the older patient are more fully described in Loewenstein, et al. (1993). Neuropsychological
Assessment
The following neuropsychological tests, which are widely utilized in the evaluation of the cognitively impaired older adult (LaRue, 1992) were administered: 1. Fuld Object Memory Evaluation (Fuld, 1977): This is a measure of memory function requiring the subject to recall ten common household objects. Interspersing recall and distractor trials, the subject is selectively reminded of those targets that are not recalled, administered a distractor task, and then again asked to recall the ten target items. The score is the total number of targets recalled summed across five learning trials. 2. Wechsler Memory Scale (Wechsler & Stone, 1945): The Logical Memory and Visual Reproduction subtests were used to assess immediate semantic and visual memory. 3. Boston Naming Test (Kaplan, Goodglass, & Weintraub, 1983): Confrontation naming abilities and word retrieval skills were measured using 60 line drawings. The total score consists of the total number of drawings spontaneously named by the subject. 4. FAS Controlled Word Association Test (Benton & Hamsher, 1977): This test of verbal fluency requires the subject to generate as many words as possible in response to a given letter. Subjects are given 1 min to generate as many words as possible that begin with the letters F, A, and S. 5. Block Design-(WAIS-R) (Wechsler, 1981): This is a measure of visuospatial abilities/praxis which required the subject to create increasingly more difficult geometric designs using blocks. 6. Object Assembly-(WAIS-R) (Wechsler, 1981): This is a test of visuoconstructive skills which required the subject to assemble four puzzles of different degrees of difficulty. 7. Similarities-(WAIS-R) (Wechsler, 1981): Abstract reasoning abilities were assessed by requiring the subjects to describe the similarities between pairs of objects or concepts. 8. Digit-Span-(WAIS-R) (Wechsler,l981): Attention and immediate memory for digits were assessed by this measure. Functional Assessment Selected Assessment
subtests of a comprehensive of Functional Status (DAFS)
functional battery, the Direct developed by Loewenstein et al.
D. A.
80
Loewensteinet al.
(1989,
1992b) were also administered to the patients. High interrater and test-retest reliabilities as well as convergent and discriminative validities have previously been established for all of the subtests of the DAFS (Loewenstein et al., 1989). Further, each of the functional domains tapped by the DAFS have been identified in the literature as important in the assessment of the older adult and have also been tapped by numerous instruments utilized in geriatric settings to assess instrumental activities of daily living (Kane & Kane, 1981). In addition to assessment of the identical functional skills required for daily living, the DAFS is unique, in that it is an objective, performance based measure that has been widely utilized with both Spanish and English-speaking groups (Loewenstein et al., 1992b; Loewenstein & Rubert, 1992). A description of each functional task is as follows: 1. Reading a Clock: Patients are asked to tell time at each of four progressively more difficult clock settings using an analog clock. 2. Telephone Skills: The patient is presented with a push-button telephone and asked to dial the operator, to dial the number of a person from a list of names and numbers, to dial a single number presented orally, and to dial a single number in written form. Such rudimentary skills as the ability to pick up the telephone receiver, dial, and hang up the receiver in proper sequence are also assessed. 3. Preparing a Letter for Mailing: The patient is required to address an envelope (the patient is provided a written name and address), write a correct return address on the envelope, place a stamp on the envelope, fold the letter, insert the letter into the envelope, and seal the envelope. 4. Counting Currency: The patient is asked to count change and paper currency over four trials of increasing difficulty. 5. Writing a Check: Patients are asked to make out a check to a party, and they are given points for writing the correct numeric and written amounts, entering the date and providing a signature. 6. Balancing a Checkbook: Patients are required to balance a checkbook at increasing levels of difficulty. These are simple subtraction problems presented in a checkbook ledger format. 7. Shopping with a Written List: Patients are asked to select 4 of 20 grocery items using a written list. More rudimentary functional tasks such as identifying currency, eating, and dressing/grooming subskills were not included in the present study as the majority of patients in our sample were not severely impaired and generally had little or no impairment in these areas. Therefore, analysis of the functional and neuropsychological relationships for these particular measures was precluded. It was our intention to first examine neuropsychological and functional relationships for Spanish-speaking and English-speaking patients separately.
NeuropsychologicaWFunctiond
Relationships in Two Cultural Groups
81
Subsequently, we analyzed the entire sample utilizing ethnicity as a predictor variable in stepwise regression models, in an attempt to more directly examine the issue of potential cultural/language bias.
RESULTS As indicated in Table 1, English-speaking AD patients tended to have slightly higher mean MMSE scores, were older and had a higher level of educational attainment relative to their Spanish-speaking counterparts. They also scored higher on several of the neuropsychological tests. To determine which predictor variables best accounted for variability in functional performance we adopted a stepwise regression approach. This allowed entry of only those variables into the equation that contributed unique or added variance to variables already entered into the model. Raw scale scores were utilized for all WAIS-R subtests as the effects of age and education were available for entry into the stepwise regression equations for both groups. Standardized regression beta weights and percentage of total variability in a functional measure, which could be accounted for by neuropsychological and other predictor variables, are presented below. As depicted in Table 2, for English-speaking AD patients, telling time was most associated with the Digit Span and Object Assembly subtest of the WAIS-R with standardized beta weights of .33 and .19, respectively (R2 = .18, p < .OOl). Utilizing the telephone was best predicted by WAIS-R Block Design (p = .29; R2 = .09, p < .OOl). Preparing a letter for mailing was best predicted by the FAS Controlled Word Association Test (B =.36), Fuld
TABLE 1 Comparative Demographic and Neuropsychological Performance Spanish-speaking and English-speaking Ad Groups English-speakers (N = 127) Age Education MMSE Fuld Boston Naming FAS Test Block Design Object Assembly Similarities Memory for Passages Memory for Designs Digit Span
77.29 12.38 20.75 18.06 33.72 25.01 4.08 3.82 5.14 4.71
(6.6) (3.5) (3.9) (9.6) (12.9) (13.1) (2. I) (2.0) (2.5) (3.8)
Spanish -speakers (N = 56) 73.36 9.61 19.11 19.04 30.27 17.93 4.43 3.84 4.02 2.34
(5.8) (5.3) (4.7) (8.6) (11.2) (8.6) (1.9) (2.2) (1.6) (3.4)
Among
p-value .OOl .OOl .029 NS NS .OOl NS NS ,008 ,037
1.52 (1.7)
1.93 (2.4)
NS
7.43 (2.5)
5.02 (2.0)
.0001
82
D. A. Loewenstein
et al.
TABLE 2 The Relationship Between Neuropsychological and Functional Status Among English-Speaking AD Patients (A’ = 127)
Functional
Task
Telling Time Using the Telephone Letter Preparation Counting Currency Writing a Check Balancing a Checkbook Shopping
with a List
Predictor Variables in the Order Selected for entry into Stepwise-Regression Equations Digit Span, Object Assembly Block Design FAS, Fuld Retrieval, Age, Object Assembly Digit Span, Fuld Retrieval FAS, Fuld Retrieval Digit Span, Visual Memory, Age, Fuld Retrieval, Object Assembly Boston Naming, Block Design
Total R2 .18* .09* .32* .16* .14* .36* .22*
*p < .OOl
Retrieval score (p = .24), age (b = .20) and performance on the Object Assembly Test (p = .18) with a total R2 = .32 (p < .OOl). Counting currency was mostly associated with Digit Span $3 = .35) and Fuld Retrieval (p = .18) with a total R2= .16 (p < .OOl). Writing a check was associated with performance on the FAS test (p = .30) and Fuld Retrieval (p = .17) and a total R2 =.14 (p < .OOl). Balancing a checkbook was associated with Digit Span (p = .37), Visual Memory (p = .16), Age (0 = .26), Fuld Retrieval (p = .16) and Object Assembly (p = .17) for a total R2 =.36 (p < .OOl). Finally, shopping with a written list was best predicted by Boston Naming (p = .32) and scores on Block Design ([3 = .26). The total R2 = .22 (p < .OOl). As observed in Table 3, a somewhat different pattern of results emerged for our Spanish-speaking patients. Telling time was most associated with performance on Block Design (0 = .31; R2 = .09, p < .05) and using the telephone TABLE 3 The Relationship Between Neuropsychological and Functional Status Among Spanish-speaking Patients with AD (N = 56)
Functional
Task
Telling Time Using the Telephone Letter Preparation Counting Currency Writing a Check Balancing a Checkbook Shopping with a List
*p < .05;**p
