Cross-national cognitive assessment in schizophrenia clinical trials: a feasibility study

Clinical trials for the treatment of schizophrenia now often include cognitive assessments in addition to clinical ratings of symptoms. Recently, these trials have included cross-national assessments. It is not clear if translated psychological tests produce consistent results across different languages. This paper presents the results of a study of the comparability of the results of cognitive assessments in different English-speaking countries and a number of countries where tests were translated into other languages. Performance on tests of executive functioning, verbal and visuo-spatial learning and memory, language skills, psychomotor speed, and vigilance was compared across the first episode patients with schizophrenia ( n=301) assessed in six different languages (English, French, Finnish, German, Hebrew, and Afrikaans), including two different countries where patients were assessed in English and other languages: Canada (French) and South Africa (Afrikaans). The variance in performance across the sites tested in English was as large as the variance between English and non-English speakers when all tests were considered. Performance differences across English and other languages were found only for executive functions, vigilance, and psychomotor speed, with executive functioning differences nonsignificant when education was considered. No differences were found between English and non-English speakers in Canada. These results suggest that the translation of tests of memory and verbal skills can lead to consistent results across translated versions of the tests. Differences between countries were greater than differences between languages, suggesting the need to consider representativeness of patient samples in terms of local educational attainment. In general, these data support the validity of cross-national neuropsychological assessments

The state of neuropsychological test norms for Spanish-speaking adults in the United States.

Objective: The present review paper aimed to identify published neuropsychological test norms developed for Spanish-speakers living in the United States (U.S.). Methods: We conducted a systematic review of the literature via an electronic search on PubMed using keywords "Normative data," "Neuropsychological test," "norms", "Hispanic/Latinos," "Spanish Speakers," and "United States." We added other studies and published manuals as identified by citations in papers from the original search. Results Eighteen sources of normative data for Spanish-speakers in the U.S. were identified. Of the 18 citations identified, only four provide normative data on comprehensive batteries of tests for Spanish-Speakers. Two of these are based on persons living in the southwest of the U.S., who tend to be of Mexican origin. Overall, a number of the studies are focused on older persons and although the majority include participants with wide ranges of education, participants in the ends of the education distribution tend to be underrepresented. Conclusion: Here we provide a detailed description of the neuropsychological normative data currently available for Spanish-speakers living in the U.S. While there has been increased attention towards developing norms for neuropsychological batteries in Spanish-speaking countries (e.g., Latin America and Spain), there is still an urgent need to standardize neuropsychological tests among diverse groups of Spanish-speaking adults living in the U.S. The present review presents a list of norms for U.S.-dwelling Spanish-speakers, thus providing an important tool for clinicians and researchers

Demographically adjusted normative data for the Halstead category test in a Spanish-speaking adult population: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS)

ObjectiveThe present study aimed to develop norms applicable to Spanish-speakers living in the United States (U.S.)- Mexico border region for the Halstead Category Test (HCT), a test of executive function.MethodsHealthy native Spanish-speakers (N = 252; Age: range 19-60 years, M = 37.28, SD = 10.24; Education: range 0-20 years; M = 10.65, SD = 4.33; 58.33% women) living in the U.S.-Mexico border region of California and Arizona completed the HCT as part of a comprehensive neuropsychological test battery. The univariable and interactive effects of demographic variables on HCT raw scores were examined. Total scores were normed using fractional polynomial equations, controlling for age, education, and gender. T-scores were also computed for HCT scores of the current Spanish-speaking normative sample using published, demographically-adjusted norms for English-speaking non-Hispanic Whites and Blacks. Impairment rates (T-Scores < 40) were calculated using published and current norms.ResultsAge was significantly associated with increased number of errors, and education and male gender were associated with decreased number of HCT errors (total raw scores). Applying norms developed for English-speaking non-Hispanic Whites and Blacks resulted in overestimation of impairment rates in the current sample (impairment: 48% with White norms and 27% with Black norms). This pattern was evident across levels of education except in participants with 13+ years of education, where rates of impairment using non-Hispanic Black norms were comparable to those based on newly developed norms.ConclusionThe present study presents norms for the HCT in a sample of U.S. Spanish-speakers, providing an important tool for identifying executive dysfunction in this population

Neurocognitive impairment in Spanish-speaking Latinos living with HIV in the US: Application of the neuropsychological norms for the US–Mexico border region in Spanish (NP-NUMBRS)

Objective Latinos in the US are at increased risk for HIV-associated neurocognitive impairment (NCI). Most studies of US Latinos living with HIV have included primarily English-speakers only. We investigated the rate, pattern, and correlates of HIV-associated NCI in native Spanish-speaking Latinos living in the US near the Mexican border. Methods Participants included 407 native Spanish-speaking Latinos (Age: M = 37.65, SD = 10.0; Education: M = 10.75, SD = 4.1; 53% male): 153 persons living with HIV (PLWH; 56% AIDS) and 254 healthy controls. All participants completed comprehensive neuropsychological assessments in Spanish. Raw neuropsychological test scores from seven domains were converted to demographically-adjusted T-scores using norms developed with healthy controls. Global and domain NCI were defined per established criteria. Among PLWH we applied norms developed for non-Hispanic (NH) Whites and Blacks, and investigated correlates of global NCI, including HIV disease characteristics and psychiatric comorbidities. Results Utilizing population specific norms, rates of global NCI were significantly higher among PLWH (39%) than healthy controls (17%), comparable to previously published rates. In contrast, rates of global NCI in the same group of PLWH were significantly different when NH White norms (63%, p < 0.0001) and NH Black norms were used (18%, p < 0.0001). Among PLWH without a history of lifetime substance use disorder, more years of antiretroviral exposure were significantly associated with decreased rates of global NCI. Conclusions Present findings lend support to the validity of newly developed norms for native Spanish-speakers living near the US-Mexico border, and underscore the importance of utilizing appropriate norms to accurately identify HIV-associated NCI

Demographically adjusted normative data for the Wisconsin Card Sorting Test-64 item: Results from the Neuropsychological Norms for the U.S.–Mexico Border Region in Spanish (NP-NUMBRS) project

ObjectiveThe Wisconsin Card Sorting Test (WCST) is among the most commonly used tests of executive functioning. We aimed to generate normative data on the 64-item version of this test (WCST-64) for Spanish-speakers living in the U.S.-Mexico Border region.MethodsParticipants included 189 native Spanish-speakers (Age: 19-60; Education: 0-20; 59.3% female) from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project who completed the WCST-64. Univariable and interactive associations between demographic variables and raw scores were examined via Spearman correlations, Wilcoxon Rank-sum tests and linear regressions. T-scores for various WCST-64 measures (Total Errors, Perseverative Responses, Perseverative Errors, Conceptual Level Responses and Number of Categories) were obtained using fractional polynomial equations with weights for age, education, and gender. Percentile scores were reported for Failures to Maintain Set. Rates of impairment (T-score < 40) were calculated by applying the newly developed norms and published norms for non-Hispanic English-speaking Whites and Blacks.ResultsOlder age was associated with worse performance and education was linked to better performance on most WCST-64 raw scores, with stronger education effects among females than males. The norms developed here resulted in expected rates of impairment (14-16% across measures). Applying published norms for non-Hispanic Blacks resulted in generally comparable impairment rates. In contrast, applying previously published norms for non-Hispanic Whites overestimated impairment (38-52% across measures).ConclusionsThese data will enhance interpretation performance on the WCST-64 for Spanish-speakers living in the U.S.-Mexico Border region. Future work will need to examine the generalizability of these norms to other Hispanic/Latino groups

Influence of Educational Background, Childhood Socioeconomic Environment, and Language Use on Cognition among Spanish-Speaking Latinos Living Near the US–Mexico Border

ObjectivesWe investigated the impact of culturally relevant social, educational, and language factors on cognitive test performance among Spanish speakers living near the US-Mexico border.MethodsParticipants included 254 healthy native Spanish speakers from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project (Age: M = 37.3, SD = 10.4; Education: M = 10.7, SD = 4.3; 59% Female). A comprehensive neuropsychological battery was administered in Spanish. Individual test scaled scores and T-scores (based on region-specific norms adjusted for age, education, and sex) were averaged to create Global Mean Scaled and T-scores. Measures of culturally relevant factors included a self-reported indicator of educational quality/access (proportion of education in Spanish-speaking country, quality of school/classroom setting, stopped attending school to work), childhood socioeconomic environment (parental education, proportion of time living in Spanish-speaking country, childhood socioeconomic and health status, access to basic resources, work as a child), and Spanish/English language use and fluency.ResultsSeveral culturally relevant variables were significantly associated with unadjusted Global Scaled Scores in univariable analyses. When using demographically adjusted T-scores, fewer culturally relevant characteristics were significant. In multivariable analyses, being bilingual (p = .04) and working as a child for one's own benefit compared to not working as a child (p = .006) were significantly associated with higher Global Mean T-score, accounting for 9% of variance.ConclusionsDemographically adjusted normative data provide a useful tool for the identification of brain dysfunction, as these account for much of the variance of sociocultural factors on cognitive test performance. Yet, certain culturally relevant variables still contributed to cognitive test performance above and beyond basic demographics, warranting further investigation

Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project: Methodology and sample characteristics.

ObjectiveThe present paper describes the methodology and sample characteristics of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project, which aimed to generate demographically-adjusted norms for a battery of neuropsychological tests in this population.MethodsThe sample consisted of 254 healthy Spanish-speakers, ages 19-60 years, recruited from the U.S.-Mexico border regions of Arizona (n = 102) and California (n = 152). Participants completed a comprehensive neuropsychological test battery assessing multiple domains (verbal fluency, speed of information processing, attention/working memory, executive function, learning and memory, visual-spatial skills and fine motor skills). Fluency in both Spanish and English was assessed with performance-based measures. Other culturally-relevant data on educational, social, and language background were obtained via self-report. Demographic influences on test performances were modeled using fractional polynomial equations that allow consideration of linear and non-linear effects.ResultsThere were no significant demographic differences between participants tested in Arizona and California. Age and gender were similar across education ranges. Two thirds of the sample were Spanish dominant and the remainder were considered bilingual. Individual articles in this Special Issue detail the generation of demographically adjusted T-scores for the various tests in the battery as well as an exploration of bilingualism effects.DiscussionNorms developed through the NP-NUMBRS project stand to improve the diagnostic accuracy of neuropsychological assessment in Spanish-speaking young-to-middle-aged adults living in the U.S.-Mexico border region. Application of the present norms to other groups should be done with caution