Demographically-adjusted norms for the paced auditory serial addition test and letter number sequencing test in Spanish-speaking adults: Results from the neuropsychological norms for the U.S.-Mexico border region in Spanish (NP-NUMBRS) Project

Objective: The Paced Auditory Serial Addition Test (PASAT) and Wechsler Adult Intelligence Scale Letter Number Sequencing subtest (LNS) are two commonly used measures of working memory. Demographic variables (age, education, ethnicity, etc.) can impact performance on these measures, underscoring the need for demographically adjusted norms. We aimed to develop normative data for the PASAT and LNS for Spanish-speaking adults living in the U.S.-Mexico border region as part of a larger normative effort. Method: Participants were native Spanish-speakers from the Neuropsychological Norms for the U.S. Mexico Border Region in Spanish (NP-NUMBRS) project. Two hundred and forty-nine participants completed the PASAT and 202 participants completed LNS. Ages ranged from 19 to 60 and education from 0 to 20 years. Results: Older age was associated with lower scores on LNS (p <.01) but not PASAT. Lower education was associated with lower scores on both tests (ps <.001). Women obtained lower raw scores than men on PASAT (ps <.003), and there were no significant main effects of gender on LNS raw scores. Raw-to-scaled score conversions were calculated, and fractional polynomial equations were developed to calculate demographically-adjusted T-scores accounting for age, education, and gender. Published norms for English-speaking non-Hispanic Whites substantially overestimated rates of impairment (defined as T-score < 40) on both the PASAT and LNS. Conclusions: The use of the population-specific normative data may improve detection of working memory dysfunction in U.S. Spanish-speaking adults and contribute to improved diagnostic accuracy and treatment planning in this population. Whether the norms generalize to U.S. Spanish-speakers from other countries remains to be determined.