Health numeracy is the understanding and application of information conveyed with numbers, tables and graphs, and probabilities in order to effectively manage one's own healthcare. Health numeracy is a vital aspect of communicating with healthcare providers and participating in one's own medical decision making, which is especially important in aging populations. Current literature indicates that assessing and establishing one's health numeracy abilities is among the first steps in providing necessary resources and accommodating patients' individual needs. Additionally, older adults with diffuse cognitive impairment often have issues with facets of executive functioning; however, the extant literature does not discuss the role of executive functioning in relation to health numeracy in this population. The purpose of this study was to explore the relationship between performance on tasks of executive functioning and objectively-measured health numeracy abilities in older adult patients.

This study included a sample of 42 older adult patients referred for neuropsychological evaluation for memory complaints who were administered the Test of Premorbid Functioning (TOPF), Trail Making Test - Part B (TMT-B), and Stroop Color and Word Test (SCWT Color Word Interference [CWI]) as part of a larger standardized battery. Patients were also administered the Numerical Understand in Medicine Instrument - Short Form (NUMI-SF). All included patients had <2 performance validity test failures. The sample was racially diverse (47.6% Black, 35.7% White, 14.3% Hispanic, 2.4% Asian) and 54.8% female. Average age was 62.95 (SD= 8.6) and average education was 14.1 (SD=2.7). Diagnostically, 47.6% of the sample were cognitively normal, 33.3% had mild cognitive impairment, and 19.0% had dementia. Average NUMI-SF score was 4.79 (SD= 1.7). Two multiple regressions were conducted to evaluate the extent to which executive functioning, as measured by the TMT-B and SCWT CWI predicted NUMI-SF, and the additive predictive power of premorbid IQ and demographics via the TOPF on the relationship between executive functioning and NUMI-SF.

The first regression, which measured the relationship between the TMT-B and SCWT CWI upon NUMI-SF scores, was not significant (p=.616). The model was significant with the addition of the TOPF (ß=.595, p<.001) and TOPF alone predicted ∼60% of the variance in NUMI-SF score, while TMT-B and SCWT CWI remained non-significant.

These results indicate that common measures of executive functioning are not reliable predictors of health literacy with or without the moderating of premorbid intellectual functioning taken into consideration. This suggests that health numeracy is likely to be minimally affected by deficits in executive functioning and rather may be better accounted for by premorbid intellectual functioning and/or other sociodemographic factors (e.g. socioeconomic status, education quality, occupation). Future studies will benefit from elucidating the contributions of other social determinant factors on predicting health numeracy.