Normative data for the Digit Symbol Substitution for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA)

Alzheimers Dement (Amst). 2024 Apr 1;16(2):e12573. doi: 10.1002/dad2.12573. eCollection 2024 Apr-Jun.

Abstract

Introduction: Executive functioning and processing speed are crucial elements of neuropsychological assessment. To meet the needs of the Hispanic/Latino population, we aimed to provide normative data for the Digit Symbol Substitution (DSS) test.

Methods: The target population for the Study of Latinos-Investigation of Neurocognitive Aging included six heritage backgrounds (n = 6177). Average age was 63.4 ± 8.3 years, 54.5% were female, and mean education was 11.0 ± 4.7 years. Participants were administered the DSS as part of a larger battery. Heritage-adjusted DSS scores, and percentile cut-points were created using survey-adjusted regression and quantile regression models.

Results: Age, education, sex, heritage, and language preference were associated with DSS scores.

Discussion: Significant correlates of DSS performance should be considered when evaluating cognitive performance. Representative DSS norms for Hispanics/Latinos will advance assessment and accuracy of neurocognitive disorder diagnosis in clinical practice. To facilitate interpretation, we provide norms to reduce test biases and developed an online dashboard.

Highlights: Normative data for the Digit Symbol Substitution (DSS) for diverse Hispanic/Latino adults: Results from the Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) This study is the first to develop norms for the DSS test across four regions of the United States.Factors such as age, education, sex, and Hispanic/Latino heritage and language preference are associated with differences in executive functioning and information processing speed.We created norms and an online dashboard (https://solincalab.shinyapps.io/dsst_shiny/) providing an easily accessible tool to evaluate processing speed and executive functioning in Hispanic/Latino adults.

Keywords: Digit Symbol Substitution test; Hispanic; aging; disparities; neuropsychology; normative data.