The Symbol Digit Modalities Test (SDMT) is a task of processing speed and executive functioning that is widely used to evaluate individuals with Multiple Sclerosis (MS) and has been shown to predict various instrumental activities of daily living. The relationship between SDMT and daily functioning has not been well explored in the aging population. The Activities of Daily Living-Prevention Instrument (ADL-PI) is a self-report measure that assesses changes in functioning and instrumental activities of daily living (IADLs). We evaluate the relationship between SDMT and ADL-PI in older adults with subjective cognitive complaints in an urban, multi-ethnic, primary care population in Bronx, New York.
300 participants (50.7% Hispanic, 43.7% non-Hispanic Black; 37% assessed in Spanish) completed the SDMT and ADL-PI as part of a larger study seeking to improve detection of cognitive impairment in primary care. The mean age of the sample was 71.35 ± 5.76 years and participants had a mean 12.26 ± 3.76 years of education. Pearson correlations were used to examine the relationship between SDMT and IADLs.
SDMT performance was weakly albeit significantly correlated with self-report of functional difficulties on the ADL-PI (r = -0.312, p < 0.001). The relationship between SDMT (Range = 1-51, M = 25.39) and ADL-PI was significant in both English (p < 0.0011) and Spanish (p = 0.004) speaking participants and remained significant when controlling for age, education, and depression (p = 0.002).
Consistent with MS literature, the SDMT is a useful tool for predicting self-report of instrumental activities of daily living of older adults with cognitive concerns.

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