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Normative data for the symbol digit modalities test in older white Australians and Americans, African-Americans, and Hispanic/Latinos


Ryan, J and Woods, RL and Britt, CJ and Murray, AM and Shah, RC and Reid, CM and Wolfe, R and Nelson, MR and Orchard, SG and Lockery, JE and Trevaks, RE and Storey, E, and on behalf of the ASPREE Investigator Group, Normative data for the symbol digit modalities test in older white Australians and Americans, African-Americans, and Hispanic/Latinos, Journal of Alzheimer's Disease Reports, 4, (1) pp. 313-323. ISSN 2542-4823 (2020) [Refereed Article]


Copyright Statement

2020 IOS Press and the authors. All rights reserved. Licensed under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

DOI: doi:10.3233/ADR-200194


Background: Processing speed, which can be assessed using the Symbol Digit Modalities Test (SDMT), is central to many brain functions. Processing speed declines with advanced age but substantial impairments are indicative of brain injury or disease.

Objective: The purpose of this study was to provide SDMT normative data for older community-dwelling individuals in the U.S. and Australia.

Methods: The ASPREE trial recruited 19,114 relatively healthy older men and women in Australia and the U.S. from the general community. All participants were without a diagnosis of dementia and with a Modified Mini-Mental State examination score of 78 or more at enrolment. The SDMT was administered at baseline as part of a neuropsychological test battery.

Results: The median age of participants was 74 years (range 65-99), and 56% were women. The median years of education was 12. Ethno-racial differences in SDMT performance were observed and normative data were thus presented separately for 16,289 white Australians, 1,082 white Americans, 891 African-Americans, and 316 Hispanic/Latinos. There were consistent positive associations found between SDMT and education level, and negative associations between SDMT and age. Mean scores for women were consistently higher than men with the exception of Hispanic/Latinos aged ≥70 years.

Conclusion: This study provides comprehensive SDMT normative data for whites (Australian and U.S.), Hispanic/Latinos, and African-Americans, according to gender, age, and education level. These norms can be used clinically as reference standards to screen for cognitive impairments in older individuals.

Item Details

Item Type:Refereed Article
Keywords:aging, symbol digit modalities test, cognition, impairment, normative data
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Cellular nervous system
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Nelson, MR (Professor Mark Nelson)
ID Code:141265
Year Published:2020
Deposited By:Menzies Institute for Medical Research
Deposited On:2020-10-08
Last Modified:2020-11-11

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