Supplementary Material for: Effects of Cognitive Functioning and Education on Later-Life Health Numeracy

Introduction: Previous studies have shown an association between a high health numeracy and good cognitive functioning. Objective: To investigate the moderation effect of education on this relationship and which brain structures support health numeracy. Methods: We examined 70 healthy older persons (66% females; mean ± SD: age, 75.73 ± 4.52 years; education, 12.21 ± 2.94 years). The participants underwent a T1-weighted 3-T MRI and a neuropsychological assessment including a health numeracy task. Statistical parametric mapping was applied to identify focal changes in cortical thickness throughout the entire brain and to correlate image parameters with behavioral measures. Results: Executive functions and mental calculation emerged as predictors of health numeracy (B = 0.22, p < 0.05, and B = 0.38, p < 0.01). An interaction was found between education and executive functions (B = –0.16, p = 0.01) and between education and mental calculation (B = –0.11, p < 0.05). Executive functions and mental calculation had an impact on health numeracy in participants with a low to intermediate edu­cation (≤12 years) but not in those with a higher education (>12 years). Health numeracy scores were associated with cortical thickness in the right dorsomedial prefrontal cortex and the right superior temporal gyrus (p = 0.01). Conclusions: Older people with a higher education perform better in health numeracy tasks than those with a lower education. They have access to previously acquired knowledge about ratio concepts and do not need to rely on executive functions and computational skills. This is highly relevant when decisions about health care have to be made.