Demographically-adjusted norms for the WAIS-R Block Design and Arithmetic subtests: Results from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project.

OBJECTIVE: Wechsler Adult Intelligence Scale (WAIS) Block Design and Arithmetic subtests are frequently used as measures of visuospatial construction and verbal working memory, respectively. As part of a larger test adaptation and norming effort for this population, we generated and investigated demographically-adjusted interpretive norms for WAIS-R Block Design and Arithmetic in Spanish-speaking adults living in the US-Mexico border region. METHOD: Participants included 183 community-dwelling adults ages 20-55 (education range: 0-20 years; 58% women) from the NeuroPsychological-Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project. They completed the WAIS-R Block Design and Arithmetic subtests in Spanish. Demographically-adjusted T-scores were calculated for these subtests using fractional polynomial equations adjusting for linear and non-linear effects of age, education (continuous), and sex. We compared our rates of impairment (i.e. T < 40) against rates calculated using published English-speaking WAIS-R standardization sample norms adjusted for age, education, and sex. RESULTS: Education was positively associated with performance on Block Design and Arithmetic subtests, and men outperformed women on both subtests. The present Spanish-speaker norms for these subtests yielded expected rates of "impairment" (i.e. 15-16% impaired, a 1 SD cutoff), while existing norms for English-speakers underestimated impairment (i.e. 5-6% impaired) when applied to our Spanish-speaking sample. CONCLUSIONS: Regional normative data will improve interpretation of test performance on Block Design and Arithmetic subtests for Spanish-speakers living in the US-Mexico border region and may aid in bolstering the overall analysis of neuropsychological profile patterns in this population. Cross-validation with Spanish-speakers in other regions and/or with other national origins is needed.

Introduction to the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project.

OBJECTIVE: The present introduction to the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project aims to provide an overview of the conceptual framework and rationale that guided the development of this project. METHODS: We describe important aspects of our conceptual framework, which was guided by some of the main purposes of neuropsychological testing, including the identification of underlying brain dysfunction, and the characterization of cognitive strengths and weakness relevant to everyday functioning. We also provide our rationale for focusing this norm development project on Spanish-speakers in the United States, and provide an outline of the articles included in this Special Issue focused on the NP-NUMBRS project. CONCLUSIONS: The data presented in this Special Issue represent an important tool for clinicians and researchers working in the neuropsychological assessment of Spanish-speakers in the United States.

Demographically-adjusted norms for the processing speed subtests of the WAIS-III in a Spanish-speaking adult population: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project.

OBJECTIVE: The Wechsler Adult Intelligence Scale (WAIS) processing speed subtests are among the most ubiquitous indices of processing speed in the field. The aim of this study was to develop and examine demographically-adjusted normative data for Spanish language versions of the WAIS-III Digit Symbol Coding (DSC) and Symbol Search (SS) subtests for US-dwelling Spanish-speakers living in the US/Mexico border region. METHODS: The sample included 203 healthy participants who were part of the larger Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project (DSC: n = 201; SS: n = 200). RESULTS: Older age and higher education were both related to lower scores on the DSC and SS subtests (all ps < .0001). There were no significant effects for gender (all ps > .05). Raw-to-scaled score conversions were calculated for both subtests, and fractional polynomial equations were derived to compute demographically-adjusted T-scores accounting for age, education, and gender for each subtest and the Processing Speed Index. Published norms for English-speaking non-Hispanic white adults slightly overestimated impairment rates (T-scores <40) on both the DSC and SS subtests, while the norms for English-speaking non-Hispanic Black/African Americans and the new NP-NUMBRS norms Spanish-speakers both yielded impairment rates that fell within expected limits for healthy controls (i.e. 13%-14%). CONCLUSIONS: This study suggests that population-specific normative data can improve the diagnostic validity of these measures for U.S.-dwelling Spanish-speakers living in the US/Mexico border region. Future research is needed to investigate the utility of these norms for other U.S.-dwelling Spanish-speaking subpopulations (e.g. Caribbean, Central American, South American).

The Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project: Overview and considerations for life span research and evidence-based practice.

OBJECTIVE: This paper summarizes the findings of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project and offers a roadmap for future research. METHODS: The NP-NUMBRS project represents the largest and most comprehensive co-normed neuropsychological battery to date for native Spanish-speaking healthy adults from the U.S. (California/Arizona)-Mexico borderland region (N = 254; ages 19-60 years). These norms provide demographic adjustments for tests across numerous domains (i.e., verbal fluency, processing speed, attention/working memory, executive function, episodic memory [learning and delayed recall], visuospatial, and fine motor skills). CONCLUSIONS: This project: 1) shows that the NP-NUMBRS norms consistently outperformed previously published norms for English-speaking non-Hispanic (White and African-American) adults in identifying impairment; 2) explores the role of Spanish-English bilingualism in test performance; and 3) provides support for the diagnostic validity of these norms in detecting HIV-associated neurocognitive impairment. Study limitations include the limited assessment of sociocultural variables and generalizability (e.g., other Latina/o populations, age limit [19 - 60 years]). Future research is needed to: 1) investigate these norms with U.S.-dwelling Spanish-speakers of non-Mexican heritage and other clinical subpopulations; 2) expand coverage of cognitive domains (e.g. language, visuospatial); 3) develop large normative datasets for children and older Latina/o populations; 4) examine how sociocultural factors impact performance (e.g., bilingualism, acculturation); 5) investigate these norms' diagnostic and ecological validity; and 6) develop norms for neurocognitive change across time. It is hoped that the NP-NUMBRS norms will aid researchers and clinicians working with U.S.-dwelling Spanish-speakers from the U.S.-Mexico borderland to conduct research and evidence-based neuropsychological evaluations in a more culturally responsive and ethical manner.