Neuropsychological Testing

Development and Validation of a Vocabulary Measure in the Mobile Toolbox

OBJECTIVE

We describe the development of a new computer adaptive vocabulary test, Mobile Toolbox (MTB) Word Meaning, and validity evidence from 3 studies.

METHOD

Word Meaning was designed to be a multiple-choice synonym test optimized for self-administration on a personal smartphone. The items were first calibrated online in a sample of 7,525 participants to create the computer-adaptive test algorithm for the Word Meaning measure within the MTB app. In Study 1, 92 participants self-administered Word Meaning on study-provided smartphones in the lab and were administered external measures by trained examiners. In Study 2, 1,021 participants completed the external measures in the lab and Word Meaning was self-administered remotely on their personal smartphones. In Study 3, 141 participants self-administered Word Meaning remotely twice with a 2-week delay on personal iPhones.

RESULTS

The final bank included 1363 items. Internal consistency was adequate to good across samples (ρxx = 0.78 to 0.81, p < .001). Test-retest reliability was good (ICC = 0.65, p < .001), and the mean theta score was not significantly different upon the second administration. Correlations were moderate to large with measures of similar constructs (ρ = 0.67-0.75, p < .001) and non-significant with measures of dissimilar constructs. Scores demonstrated small to moderate correlations with age (ρ = 0.35 to 0.45, p < .001) and education (ρ = 0.26, p < .001).

CONCLUSION

The MTB Word Meaning measure demonstrated evidence of reliability and validity in three samples. Further validation studies in clinical samples are necessary.

Clinical value of Alzheimer's disease biomarker testing

INTRODUCTION

In the Investigating the Impact of Alzheimer's Disease Diagnostics in British Columbia (IMPACT-AD BC) study, we aimed to understand how Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarker testing-used in medical care-impacted medical decision-making (medical utility), personal decision-making (personal utility), and health system economics.

METHODS

The study was designed as an observational, longitudinal cohort study. A total of 149 patients were enrolled between February 2019 and July 2021. Patients referred to memory clinics were approached to participate if their dementia specialist ordered AD CSF biomarker testing as part of their routine medical care, and the clinical scenario met the appropriate use criteria for lumbar puncture and AD CSF biomarker testing. For the medical utility pillar, detailed clinical management plans were collected via physician questionnaires pre- and post-biomarker disclosure.

RESULTS

Patients with completed management questionnaires (n = 142) had a median age of 64 (interquartile range: 59-69) years, 48% were female, and 60% had CSF biomarker profiles on the AD continuum. Clinical management changed in 89.4% of cases. AD biomarker testing was associated with decreased need for other diagnostic procedures, including brain imaging (-52.0%) and detailed neuropsychological assessments (-63.2%), increased referrals and counseling (57.0%), and guided AD-related drug prescriptions (+88.4% and -50.0% in biomarker-positive and -negative cases, respectively).

DISCUSSION

AD biomarker testing was associated with significant and positive changes in clinical management, including decreased health care resource use, therapy optimization, and increased patient and family member counseling. While certain changes in management were linked to the AD biomarker profile (e.g., referral to clinical trials), the majority of changes were independent of baseline clinical presentation and level of cognitive impairment, demonstrating a broad value for AD biomarker testing in individuals meeting the appropriate use criteria for testing.

The influence of early life socio-environmental factors on executive performance in a healthy adult sample

OBJECTIVE

Attempts have been made (with research efforts encouraged) to deconstruct the "race" concept into language, cultural, and life experience variables that can help explain performance differences found between ethnic groups (Romero et al., 2009). The extant empirical literature reveals that early environmental factors and life experiences (e.g., socioeconomic status) are related to cognitive test performance in adulthood (Byrd et al., 2006). This study examined the explanatory value of early life childhood resources in the relationship between ethnicity and neuropsychological test performance in adulthood.

PARTICIPANTS/ METHODS

Neurologically and psychologically healthy African American (n = 40), Caucasian (n = 14), and Hispanic (n = 107) college students ranging from 19-38 years of age. On average, participants had completed around 13 years of education, indicating that the majority were in the early stages of their undergraduate studies and mostly consisted of females (72%). Each participant completed a comprehensive neuropsychological battery that included tests of executive function and an extensive background questionnaire.

RESULTS

A one-way analysis of variance (ANOVA) revealed that the CA group was significantly older (F (2, 160) = 18.38, p = .045) compared to the AA and H groups, but the groups did not differ in terms of number of years of educations or gender. Also, an ANOVA revealed significant group test performance differences on the Stroop-C [F (2, 160) = 1.53, p = .047], but not on the TMT-B and COWAT. Furthermore, a Tukey post hoc revealed that there were no significant differences in test performance on Stroop-C between the groups. Hierarchical multiple regression analyses revealed that group performance differences on executive function tests were medium or non-existent and only partially explained by years of education and early life financial resources.

CONCLUSION

The results are discussed in light of the existing literature, study strengths and limitations, as well as directions for future research. This research can aid in pinpointing variables crucial for interpreting differences in neuropsychological assessments among diverse populations, holding potential implications for intervention research and policy settings. It is particularly relevant in the context of the continuously evolving social, political, and economic landscapes of societies.

Personality predictors of dementia diagnosis and neuropathological burden: An individual participant data meta-analysis

INTRODUCTION

The extent to which the Big Five personality traits and subjective well-being (SWB) are discriminatory predictors of clinical manifestation of dementia versus dementia-related neuropathology is unclear.

METHODS

Using data from eight independent studies (Ntotal = 44,531; Ndementia = 1703; baseline Mage = 49 to 81 years, 26 to 61% female; Mfollow-up range = 3.53 to 21.00 years), Bayesian multilevel models tested whether personality traits and SWB differentially predicted neuropsychological and neuropathological characteristics of dementia.

RESULTS

Synthesized and individual study results indicate that high neuroticism and negative affect and low conscientiousness, extraversion, and positive affect were associated with increased risk of long-term dementia diagnosis. There were no consistent associations with neuropathology.

DISCUSSION

This multistudy project provides robust, conceptually replicated and extended evidence that psychosocial factors are strong predictors of dementia diagnosis but not consistently associated with neuropathology at autopsy.

HIGHLIGHTS

N(+), C(-), E(-), PA(-), and NA(+) were associated with incident diagnosis. Results were consistent despite self-report versus clinical diagnosis of dementia. Psychological factors were not associated with neuropathology at autopsy. Individuals with higher conscientiousness and no diagnosis had less neuropathology. High C individuals may withstand neuropathology for longer before death.

A Tablet-Based Aphasia Assessment System "STELA": Feasibility and Validation Study

BACKGROUND

There is an extensive library of language tests, each with excellent psychometric properties; however, many of the tests available take considerable administration time, possibly bearing psychological strain on patients. The Short and Tailored Evaluation of Language Ability (STELA) is a simplified, tablet-based language ability assessment system developed to address this issue, with a reduced number of items and automated testing process.

OBJECTIVE

The aim of this paper is to assess the administration time, internal consistency, and validity of the STELA.

METHODS

The STELA consists of a tablet app, a microphone, and an input keypad for clinician's use. The system is designed to assess language ability with 52 questions grouped into 2 comprehension modalities (auditory comprehension and reading comprehension) and 3 expression modalities (naming and sentence formation, repetition, and reading aloud). Performance in each modality was scored as the correct answer rate (0-100), and overall performance expressed as the sum of modality scores (out of 500 points).

RESULTS

The time taken to complete the STELA was significantly less than the time for the WAB (mean 16.2, SD 9.4 vs mean 149.3, SD 64.1 minutes; P<.001). The STELA's total score was strongly correlated with the WAB Aphasia Quotient (r=0.93, P<.001), supporting the former's concurrent validity concerning the WAB, which is a gold-standard aphasia assessment. Strong correlations were also observed at the subscale level; STELA auditory comprehension versus WAB auditory comprehension (r=0.75, P<.001), STELA repetition versus WAB repetition (r=0.96, P<.001), STELA naming and sentence formation versus WAB naming and word finding (r=0.81, P<.001), and the sum of STELA reading comprehension or reading aloud versus WAB reading (r=0.82, P<.001). Cronbach α obtained for each modality was .862 for auditory comprehension, .872 for reading comprehension, .902 for naming and sentence formation, .787 for repetition, and .892 for reading aloud. Global Cronbach α was .961. The average of the values of item-total correlation to each subscale was 0.61 (SD 0.17).

CONCLUSIONS

Our study confirmed significant time reduction in the assessment of language ability and provided evidence for good internal consistency and validity of the STELA tablet-based aphasia assessment system.

Understanding racial differences in computerized neurocognitive test performance and symptom-reporting to deliver culturally competent patient-centered care for sport-related concussion

OBJECTIVE

This study examined neurocognitive performance and symptoms between concussed Black and White collegiate athletes at baseline, post-injury, and change from baseline to post-injury.

METHOD

The Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) was used to measure neurocognitive performance and four concussion symptom clusters for 235 concussed collegiate athletes. Between-groups differences were documented at baseline and post-injury, along with change in scores for sex/race, and sport/race groups, using ANOVAs. Baseline scores, and days-to-post-test were covariates in post-injury comparisons. Symptom endorsement by race was evaluated using chi-square analyses.

RESULTS

At baseline, group comparisons by race and sex showed that Black male/female athletes scored lower on reaction time (RT; p = .008), White females scored higher on verbal memory (VerbMem; p = .001), Black females scored lower on visual motor processing speed (VMS; p = .001), and Black football athletes scored slower/poorer on RT (p = .001) and VMS (p = .006). Post-injury, Black males scored lower on visual memory (VisMem; p = .005) and VMS (p = .002), and Black football athletes scored slower on VMS (p = .005), whereas White non-football athletes scored higher on VerbMem (p = .002) and reported fewer symptoms. Significant time-by-sport/race interactions were found for VerbMem (p < .001), VisMem (p < .001) and reported symptoms. With respect to post-injury symptom scores/endorsement, Black athletes scored significantly higher for physical (p = .01) and sleep (p = .01) symptoms.

CONCLUSION

These findings drive the conversation of how subjective measures of symptoms, and objective clinical concussion measures, may relate to the concussion recovery process and providing a culturally competent clinical management approach for diverse patients.

Validation of a digit symbol substitution test for use in supervised and unsupervised assessment in mild Alzheimer's disease

INTRODUCTION

The Digit-Symbol-Substitution Test (DSST) is used widely in neuropsychological investigations of Alzheimer's Disease (AD). A computerized version of this paradigm, the DSST-Meds, utilizes medicine-date pairings and has been developed for administration in both supervised and unsupervised environments. This study determined the utility and validity of the DSST-Meds for measuring cognitive dysfunction in early AD.

METHOD

Performance on the DSST-Meds was compared to performance on the WAIS Coding test, and a computerized digit symbol coding test (DSST-Symbols). The first study compared supervised performance on the three DSSTs versions in cognitively unimpaired (CU) adults (n = 104). The second compared supervised DSST performance between CU (n = 60) and mild-symptomatic AD (mild-AD, n = 79) groups. The third study compared performance on the DSST-Meds between unsupervised (n= 621) and supervised settings.

RESULTS

In Study 1, DSST-Meds accuracy showed high correlations with the DSST-Symbols accuracy (r = 0.81) and WAIS-Coding accuracy (r = 0.68). In Study 2, when compared to CU adults, the mild-AD group showed lower accuracy on all three DSSTs (Cohen's d ranging between 1.39 and 2.56) and DSST-Meds accuracy was correlated moderately with Mini-Mental State Examination scores (r = 0.44, p < .001). Study 3 observed no difference in DSST-meds accuracy between supervised and unsupervised administrations.

CONCLUSION

The DSST-Meds showed good construct and criterion validity when used in both supervised and unsupervised contexts and provided a strong foundation to investigate the utility of the DSST in groups with low familiarity to neuropsychological assessment.

Intercultural care for people of migrant origin with dementia - A literature analysis

BACKGROUND

Close to 12 million people of migrant origin who are 65 years or older live in different European countries. In the European Union (EU) and the European Free Trade Association (EFTA) countries, approximately half a million are estimated to have dementia. This rate is expected to increase in the coming decades. People of migrant origin who develop dementia and their families face challenges people without migration backgrounds do, but due to cultural differences, additional challenges may arise. There is an increasing need for interculturally sensitive care. There is research on certain aspects of intercultural care and this study will be a comprehensive summary of current topics in intercultural care.

RESEARCH QUESTION

What factors of intercultural care for people of migrant origin with dementia can be identified? What requirements and aspects are necessary to ensure intercultural care?

METHOD

A systematic literature analysis in the databases PubMed, PsycInfo and Psychology and Behavioural Sciences Collection was conducted.

FINDINGS

Thirty-nine articles were eligible for analysis. Enhancement in the areas diagnostics, education and information, healthcare services and healthcare professionals to ensure intercultural care is needed.

DISCUSSION

Current evidence supports the need for (a) thorough education of people of migrant origin with dementia, their families and healthcare professionals, (b) collaborations among everyone involved, (c) embracing different cultures in healthcare services, (d) the implementation of a care navigator functioning as a contact person and connecting all relevant parties with one another and (e) dementia testing suitable to the target group to ensure culturally sensitive and appropriate care for people of migrant origin with dementia and their families.

Rationale and Design of the National Neuropsychology Network

OBJECTIVE

The National Neuropsychology Network (NNN) is a multicenter clinical research initiative funded by the National Institute of Mental Health (NIMH; R01 MH118514) to facilitate neuropsychology's transition to contemporary psychometric assessment methods with resultant improvement in test validation and assessment efficiency.

METHOD

The NNN includes four clinical research sites (Emory University; Medical College of Wisconsin; University of California, Los Angeles (UCLA); University of Florida) and Pearson Clinical Assessment. Pearson Q-interactive (Q-i) is used for data capture for Pearson published tests; web-based data capture tools programmed by UCLA, which serves as the Coordinating Center, are employed for remaining measures.

RESULTS

NNN is acquiring item-level data from 500-10,000 patients across 47 widely used Neuropsychology (NP) tests and sharing these data via the NIMH Data Archive. Modern psychometric methods (e.g., item response theory) will specify the constructs measured by different tests and determine their positive/negative predictive power regarding diagnostic outcomes and relationships to other clinical, historical, and demographic factors. The Structured History Protocol for NP (SHiP-NP) helps standardize acquisition of relevant history and self-report data.

CONCLUSIONS

NNN is a proof-of-principle collaboration: by addressing logistical challenges, NNN aims to engage other clinics to create a national and ultimately an international network. The mature NNN will provide mechanisms for data aggregation enabling shared analysis and collaborative research. NNN promises ultimately to enable robust diagnostic inferences about neuropsychological test patterns and to promote the validation of novel adaptive assessment strategies that will be more efficient, more precise, and more sensitive to clinical contexts and individual/cultural differences.

Identifying relevant outcomes in the progression of Alzheimer's disease; what do patients and care partners want to know about prognosis?

BACKGROUND

Prognostic studies in the context of Alzheimer's disease (AD) mainly predicted time to dementia. However, it is questionable whether onset of dementia is the most relevant outcome along the AD disease trajectory from the perspective of patients and their care partners. Therefore, we aimed to identify the most relevant outcomes from the viewpoint of patients and care partners.

METHODS

We used a two-step, mixed-methods approach. As a first step we conducted four focus groups in the Netherlands to elicit a comprehensive list of outcomes considered important by patients (n = 12) and care partners (n = 14) in the prognosis of AD. The focus groups resulted in a list of 59 items, divided into five categories. Next, in an online European survey, we asked participants (n = 232; 99 patients, 133 care partners) to rate the importance of all 59 items (5-point Likert scale). As participants were likely to rate a large number of outcomes as "important" (4) or "very important" (5), we subsequently asked them to select the three items they considered most important.

RESULTS

The top-10 lists of items most frequently mentioned as "most important" by patients and care partners were merged into one core outcome list, comprising 13 items. Both patients and care partners selected outcomes from the category "cognition" most often, followed by items in the categories "functioning and dependency" and "physical health." No items from the category "behavior and neuropsychiatry" and "social environment" ended up in our core list of relevant outcomes.

CONCLUSION

We identified a core list of outcomes relevant to patients and care partner, and found that prognostic information related to cognitive decline, dependency, and physical health are considered most relevant by both patients and their care partners.

Examination of Regression-based Discrepancy Scores for the RBANS in Detecting Cognitive Impairment from an Archival Sample

OBJECTIVE

The purpose of this study was to evaluate the clinical utility of regression-based formulas for the RBANS indexes in screening for cognitive impairment.

METHOD

A database of neuropsychological test results was created from archival records in a memory assessment clinic. The sample consisted of 83 individuals (37 males/46 females) with an average age of 70.1 (SD = 9.8) and 14.6 years of education (SD = 2.8). Diagnostic accuracy of regression-based predictions provided by Duff and Ramezani (2015) (Duff, K., & Ramezani, A. (2015). Regression-based normative formulae for the Repeatable Battery for the Assessment of Neuropsychological Status for older adults. Archives of Clinical Neuropsychology, 30, 600-604.) and from regression of WTAR standard score were examined via receiver operator characteristic curves. Preliminary generalizability investigation was completed using two additional datasets.

RESULTS

The WTAR was found to mediate the relationship between education and all RBANS index scores. The WTAR standard score was also found to contribute uniquely and significantly to the prediction of RBANS performance. Results of diagnostic accuracy analyses showed similar discriminating accuracy for all scores. There was limited support for using the WTAR over demographic variables alone in the estimation of RBANS performance; however, the WTAR was found to be more predictive than education, indicating potential clinical utility to using the word-reading score over just years of attained education.

CONCLUSIONS

Use of these derived Total Scale score variants is recommended for the screening of cognitive impairment, particularly in individuals with superior or poor educational quality. Further research is required to evaluate the utility of these variations in more diverse samples.

An investigation of the use of standardised leaving certificate performance as a method of estimating pre-morbid intelligence

BACKGROUND

In cases of brain pathology, current levels of cognition can only be interpreted reliably relative to accurate estimations of pre-morbid functioning. Estimating levels of pre-morbid intelligence is, therefore, a crucial part of neuropsychological evaluation. However, current methods of estimation have proven problematic.

OBJECTIVE

To evaluate if standardised leaving certificate (LC) performance can predict intellectual functioning in a healthy cohort. The LC is the senior school examination in the Republic of Ireland, taken by almost 50 000 students annually, with total performance distilled into Central Applications Office points.

METHODS

A convenience sample of university students was recruited (n = 51), to provide their LC results and basic demographic information. Participants completed two cognitive tasks assessing current functioning (Vocabulary and Matrix Reasoning (MR) subtests - Wechsler Abbreviated Scale of Intelligence, Second Edition) and a test of pre-morbid intelligence (Spot-the-Word test from the Speed and Capacity of Language Processing). Separately, LC results were standardised relative to the population of test-takers, using a computer application designed specifically for this project.

RESULTS

Hierarchical regression analysis revealed that standardised LC performance [F(2,48) = 3.90, p = 0.03] and Spot-the-Word [F(2,47) = 5.88, p = 0.005] significantly predicted current intellect. Crawford & Allen's demographic-based regression formula did not. Furthermore, after controlling for gender, English [F(1,49) = 11.27, p = 0.002] and Irish [F(1,46) = 4.06, p = 0.049) results significantly predicted Vocabulary performance, while Mathematics results significantly predicted MR [F(1,49) = 8.80, p = 0.005].

CONCLUSIONS

These results suggest that standardised LC performance may represent a useful resource for clinicians when estimating pre-morbid intelligence.

Factors Contributing to Disparities in Baseline Neurocognitive Performance and Concussion Symptom Scores Between Black and White Collegiate Athletes

BACKGROUND

National Collegiate Athletic Association (NCAA) concussion guidelines state that all NCAA athletes must have a concussion baseline test prior to commencing their competitive season. To date, little research has examined potential racial differences on baseline neurocognitive performance among NCAA athletes. The purpose of this study was to investigate differences between Black and White collegiate athletes on baseline neurocognitive performance and self-reported symptoms.

METHODS

A total of 597 collegiate athletes (400 White, 197 Black) participated in this study. Athletes self-reported their race on the demographic section of their pre-participation physical examination and were administered the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) neurocognitive battery in a supervised, quiet room. Controlling for sex, data were analyzed using separate one-way analyses of covariance (ANCOVAs) on symptom score, verbal and visual memory, visual motor processing speed, and reaction time composite scores.

RESULTS

Results revealed significant differences between White and Black athletes on baseline symptom score (F (1,542) = 5.82, p = .01), visual motor processing speed (F (1,542) = 14.89, p < .001), and reaction time (F (1,542) = 11.50, p < .01). White athletes performed better than Black athletes on baseline visual motor processing speed and reaction time. Black athletes reported higher baseline symptom scores compared to Whites. There was no statistical difference between race on verbal memory (p = .08) and that on visual memory (p = .06).

CONCLUSIONS

Black athletes demonstrated disparities on some neurocognitive measures at baseline. These results suggest capturing an individual baseline on each athlete, as normative data comparisons may be inappropriate for athletes of a racial minority.

Development of the Korean Adult Reading Test (KART) to estimate premorbid intelligence in dementia patients

We aimed to develop a word-reading test for Korean-speaking adults using irregularly pronounced words that would be useful for estimation of premorbid intelligence. A linguist who specialized in Korean phonology selected 94 words that have irregular relationship between orthography and phonology. Sixty cognitively normal elderly (CN) and 31 patients with Alzheimer's disease (AD) were asked to read out loud the words and were administered the Wechsler Adult Intelligence Scale, 4th edition, Korean version (K-WAIS-IV). Among the 94 words, 50 words that did not show a significant difference between the CN and the AD group were selected and constituted the KART. Using the 30 CN calculation group (CNc), a linear regression equation was obtained in which the observed full-scale IQ (FSIQ) was regressed on the reading errors of the KART, where education was included as an additional variable. When the regressed equation computed from the CNc was applied to 30 CN individuals of the validation group (CNv), the predicted FSIQ adequately fit the observed FSIQ (R2 = 0.63). In addition, independent sample t-test showed that the KART-predicted IQs were not significantly different between the CNv and AD groups, whereas the performance of the AD group was significantly worse in the observed IQs. In addition, an extended validation of the KART was performed with a separate sample consisted of 84 CN, 56 elderly with mild cognitive impairment (MCI), and 43 AD patients who were administered comprehensive neuropsychological assessments in addition to the KART. When the equation obtained from the CNc was applied to the extended validation sample, the KART-predicted IQs of the AD, MCI and the CN groups did not significantly differ, whereas their current global cognition scores significantly differed between the groups. In conclusion, the results support the validity of KART-predicted IQ as an index of premorbid IQ in individuals with AD.

Comparing recruitment, retention, and safety reporting among geographic regions in multinational Alzheimer's disease clinical trials

INTRODUCTION

Most Alzheimer's disease (AD) clinical trials enroll participants multinationally. Yet, few data exist to guide investigators and sponsors regarding the types of patients enrolled in these studies and whether participant characteristics vary by region.

METHODS

We used data derived from four multinational phase III trials in mild to moderate AD to examine whether regional differences exist with regard to participant demographics, safety reporting, and baseline scores on the Mini Mental State Examination (MMSE), the 11-item Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-cog11), the Clinical Dementia Rating scale Sum of Boxes (CDR-SB), the Alzheimer's Disease Cooperative Study-Activities of Daily Living Inventory (ADCS-ADL), and the Neuropsychiatric Inventory (NPI). We assigned 31 participating nations to 7 geographic regions: North America, South America/Mexico, Western Europe/Israel, Eastern Europe/Russia, Australia/South Africa, Asia, and Japan.

RESULTS

North America, Western Europe/Israel, and Australia/South Africa enrolled similar proportions of men, apolipoprotein E ε4 carriers, and participants with spouse study partners, whereas Asia, Eastern Europe/Russia, and South America/Mexico had lower proportions for these variables. North America and South America/Mexico enrolled older subjects, whereas Asia and South America/Mexico enrolled less-educated participants than the remaining regions. Approved AD therapy use differed among regions (range: 73% to 92%) and was highest in North America, Western Europe/Israel, and Japan. Dual therapy was most frequent in North America (48%). On the MMSE, North America, Western Europe/Israel, Japan, and Australia/South Africa had higher (better) scores, and Asia, South America/Mexico, and Eastern Europe/Russia had lower scores. Eastern Europe/Russia had more impaired ADAS-cog11 scores than all other regions. Eastern Europe/Russia and South America/Mexico had more impaired scores for the ADCS-ADL and the CDR-SB. Mean scores for the CDR-SB in Asia were milder than all regions except Japan. NPI scores were lower in Asia and Japan than in all other regions. Participants in North America and Western Europe/Israel reported more adverse events than those in Eastern Europe/Russia and Japan.

CONCLUSIONS

These findings suggest that trial populations differ across geographic regions on most baseline characteristics and that multinational enrollment is associated with sample heterogeneity. The data provide initial guidance with regard to the regional differences that contribute to this heterogeneity and are important to consider when planning global trials.

Reliability and validity of the short form of the literacy-independent cognitive assessment in the elderly

BACKGROUND AND PURPOSE

The Literacy-Independent Cognitive Assessment (LICA) has been developed for a diagnosis of dementia and is a useful neuropsychological test battery for illiterate populations as well as literate populations. The objective of this study was to develop the short form of the LICA (S-LICA) and to evaluate the reliability and validity of the S-LICA.

METHODS

The subtests of the S-LICA were selected based on the factor analysis and validation study results of the LICA. Patients with dementia (n=101) and normal elderly controls (n=185) participated in this study.

RESULTS

Cronbach's coefficient alpha of the S-LICA was 0.92 for illiterate subjects and 0.94 for literate subjects, and the item-total correlation ranged from 0.63 to 0.81 (p<.01).The test-retest reliability of the S-LICA total score was high (r=0.94, p<.001), and the subtests had high test-retest reliabilities (r=0.68-0.87, p<.01). The correlation between the K-MMSE and S-LICA total scores were substantial in both the illiterate subjects (r=0.837, p<.001) and the literate subjects(r=0.802, p<.001). The correlation between the S-LICA and LICA was very high (r=0.989, p<.001). The area under the curve of the receiver operating characteristic was 0.999 for the literate subjects and 0.985 for the illiterate subjects. The sensitivity and specificity of the S-LICA for a diagnosis of dementia were 97% and 96% at the cutoff point of 72 for the literate subjects, and 96% and 93% at the cutoff point of 68 for the illiterate subjects, respectively.

CONCLUSIONS

Our results indicate that the S-LICA is a reliable and valid instrument for quick evaluation of patients with dementia in both illiterate and literate elderly populations.

Estimating premorbid cognitive abilities in low-educated populations

Objective

To develop an informant-based instrument that would provide a valid estimate of premorbid cognitive abilities in low-educated populations.

Methods

A questionnaire was drafted by focusing on the premorbid period with a 10-year time frame. The initial pool of items was submitted to classical test theory and a factorial analysis. The resulting instrument, named the Premorbid Cognitive Abilities Scale (PCAS), is composed of questions addressing educational attainment, major lifetime occupation, reading abilities, reading habits, writing abilities, calculation abilities, use of widely available technology, and the ability to search for specific information. The validation sample was composed of 132 older Brazilian adults from the following three demographically matched groups: normal cognitive aging (n = 72), mild cognitive impairment (n = 33), and mild dementia (n = 27). The scores of a reading test and a neuropsychological battery were adopted as construct criteria. Post-mortem inter-informant reliability was tested in a sub-study with two relatives from each deceased individual.

Results

All items presented good discriminative power, with corrected item-total correlation varying from 0.35 to 0.74. The summed score of the instrument presented high correlation coefficients with global cognitive function (r = 0.73) and reading skills (r = 0.82). Cronbach's alpha was 0.90, showing optimal internal consistency without redundancy. The scores did not decrease across the progressive levels of cognitive impairment, suggesting that the goal of evaluating the premorbid state was achieved. The intraclass correlation coefficient was 0.96, indicating excellent inter-informant reliability.

Conclusion

The instrument developed in this study has shown good properties and can be used as a valid estimate of premorbid cognitive abilities in low-educated populations. The applicability of the PCAS, both as an estimate of premorbid intelligence and cognitive reserve, is discussed.

Psychiatric and demographic predictors of memory deficits in African Americans with schizophrenia: the moderating role of cultural mistrust

Although African Americans are overrepresented among schizophrenia diagnoses, assessments of memory deficits in schizophrenia often do not consider issues of race, ethnicity, and culture. Digit span testing (DST) is often used to assess memory problems associated with schizophrenia. The purpose of the current study was to examine the effects of psychiatric symptoms and demographic background on the DST performances of 128 African American schizophrenic patients. It was hypothesized that level of cultural mistrust would moderate the relationship of psychiatric and demographic variables to memory deficits. The study involved the secondary analysis of data from the Culturally-Sensitive Diagnostic Interview Research Project. Different models of the relationship among predictor variables in their impact on DST performance were tested via structural equation modeling (SEM); and the moderating effects of level of cultural mistrust were evaluated with the best SEM model. The results supported the hypothesis that level of cultural mistrust moderates the relationship among variables in the SEM model. Specifically, psychiatric symptoms negatively impacted DST performance in the low cultural mistrust group, but they had no significant association to the memory deficits of the high cultural mistrust group. The pattern of findings for the effects of psychiatric symptoms on DST performance is consistent with the view of cultural mistrust as an adaptive mechanism in African Americans. One implication is that cultural factors should be taken into account when assessing memory deficits in African Americans with schizophrenia.

Screening for HIV-associated dementia in South Africa: potentials and pitfalls of task-shifting

There is an urgent need for valid, reliable, and simple-to-use screening tools for HIV-associated dementia (HAD) in South Africa, as little is known about its impact on South Africa's 5.5 million people living with HIV (PLWH). Screening for HAD in South Africa involves several challenges, including few culturally appropriate and validated screening tools, and a shortage of trained personnel to conduct screening. This study examined rates of positive HAD screens as determined by the cutoff score on the International HIV Dementia Scale (IHDS) administered by nonspecialist community health workers (CHWs) in South Africa and examined associations between positive HAD screens and common risk factors for HAD. Sixty-five Xhosa-speaking HIV-positive individuals on antiretroviral therapy (ART) with low CD4 counts and documented ART adherence problems were administered a battery of demographic, psychiatric and neurocognitive screening measures. Positive HAD screens were present in 80% of the sample. Presence of a current alcohol dependence disorder and CD4 counts of 200 or lower were significantly associated with positive HAD screens. HIV-positive South Africans on ART with low CD4 counts and ART adherence problems may be at a very high risk for HAD, highlighting the need for more routine screening and monitoring of neurocognitive functions among South Africa's millions of PLWH on ART. Future research is needed to: (1) validate IHDS performance against a gold standard neurocognitive battery for the detection of HAD among larger samples of Xhosa-speaking South Africans with ART adherence difficulties and (2) compare performance of CHW to expert health care personnel in administering the IHDS.

Explaining differences in episodic memory performance among older African Americans and Whites: the roles of factors related to cognitive reserve and test bias

Older African Americans tend to perform poorly in comparison with older Whites on episodic memory tests. Observed group differences may reflect some combination of biological differences, measurement bias, and other confounding factors that differ across groups. Cognitive reserve refers to the hypothesis that factors, such as years of education, cognitive activity, and socioeconomic status, promote brain resilience in the face of pathological threats to brain integrity in late life. Educational quality, measured by reading test performance, has been postulated as an important aspect of cognitive reserve. Previous studies have not concurrently evaluated test bias and other explanations for observed differences between older African Americans and Whites. We combined data from two studies to address this question. We analyzed data from 273 African American and 720 White older adults. We assessed DIF using an item response theory/ordinal logistic regression approach. DIF and factors associated with cognitive reserve did not explain the relationship between race, and age- and sex-adjusted episodic memory test performance. However, reading level did explain this relationship. The results reinforce the importance of considering education quality, as measured by reading level, when assessing cognition among diverse older adults.

The importance and challenges of assessing cognition in Indigenous Australians

OBJECTIVES

The aim of this paper was to investigate the importance and challenges involved in conducting serial cognitive assessments among healthy Indigenous adolescents.

METHOD

Cognitive assessments were conducted at fortnightly intervals for 2 months and again at 6 and 12 months among a group of Indigenous students from a boarding school in the Northern Territory. These students were to be the healthy control group in a long-term study of substance abuse. Recruitment and attrition rates were reviewed and related challenges for assessing participants were identified.

RESULTS

From the recruited sample (n=49), 18% reported heavy or frequent use of alcohol, cannabis or petrol. Males were more likely to have used these substances compared to females. Attrition increased as the follow-up interval increased with 49 recruits reducing to 32 in the first 2 months and only 15 and 13 of the initial group remaining for the 6 and 12 month follow-ups respectively.

CONCLUSIONS

Main challenges included (i) appropriateness of tests and assessment processes, (ii) high rates of substance abuse and other illness in the control group and (iii) high attrition rates. The importance of assessing cognition appropriately is highlighted by a lack of information regarding mental health issues in Indigenous populations.

Informant-based dementia screening in a population-based sample of African Americans

BACKGROUND

An informant-based screening tool for dementia may be useful in population-based studies of minority populations.

OBJECTIVE

Investigate the feasibility of screening for very mild dementia in a community sample of African Americans using an informant-based screening tool (AD8).

DESIGN

Cohort study.

PARTICIPANTS

One hundred forty-seven persons from the African American Health (AAH) project were screened for dementia; 61 of 93 who were invited had follow-up clinical assessments for dementia diagnosis.

MEASUREMENTS

The AD8, Mini-Mental State Examination, Short Blessed Test, Brief Instrument for Dementia Detection, and a neuropsychologic battery were administered at visit 1. The Clinical Dementia Rating (CDR) was administered at visit 2 by clinicians blinded to visit 1 results; the presence of dementia was determined by a CDR greater than 0.

RESULTS

Four hundred sixty-five individuals from the AAH cohort were sent a letter describing the study and, among this group, 252 individuals were contacted by phone to request participation in this study. Six percent (14/252) of the participants contacted by phone were unable to identify an informant (required for the AD8). One hundred fifty individuals agreed by phone to participate of which 2% (n=3) did not have an informant available at the time of participation. The AD8 alone was effective at discriminating between CDR 0 and CDR 0.5 (area under the curve=0.847; P<0.001; 95% confidence interval, 0.73-0.96).

CONCLUSIONS

A brief informant-based instrument, the AD8, has high sensitivity and specificity for distinguishing CDR 0 from CDR 0.5 in the community. Informant availability may not be a barrier for using the AD8 in an African American community sample; however, further study in larger samples with a higher response rate, different community settings (eg, community clinics), and among older age groups (eg, age 75+) is warranted to confirm this.

Psychotropic medication use and cognition in institutionalized older adults with mild to moderate dementia

BACKGROUND

Most studies examining psychotropic medication use on cognition in older persons with dementia include measures of global cognitive function. The present study examined the relationship between different types of psychotropic medication and specific cognitive functions in older people with dementia.

METHODS

Two hundred and six institutionalized older adults with dementia (180 women, mean age 85 years) were administered neuropsychological tests. Psychotropic medication use was extracted from their medical status and categorized as: sedatives, antidepressants and antipsychotics.

RESULTS

Analysis of covariance revealed that psychotropic consumers, and particularly those who used antipsychotics, performed worse on neuropsychological tests of executive/attentional functioning than non-consumers. There were no differences between consumers of other classes of psychotropic drugs and non-consumers. The number of psychotropic drugs used was inversely related to executive/attentional functioning.

CONCLUSIONS

These findings show that in institutionalized older adults with dementia, specific impairment of cognitive function, i.e. executive/attentional impairments, are associated with antipsychotic medication use. Future longitudinal studies are recommended.