The Moderating Role of Digital Literacy in the Relationship Between Cognitive Function and Instrumental Activities of Daily Living Among Community-Dwelling Older Adults

Background: As population aging accelerates, maintaining functional independence among older adults has become a critical public health priority. Cognitive function is a well-established determinant of instrumental activities of daily living (IADL); however, the role of digital literacy in shaping this relationship remains unclear. In the context of increasing digitalization, digital literacy may serve as a key factor supporting aging in place. Therefore, this study aimed to examine the moderating effect of digital literacy on the relationship between cognitive function and IADL among community-dwelling older adults. Methods: This descriptive cross-sectional study was conducted among 147 community-dwelling older adults aged 75 years and older. Cognitive function was assessed using the Korean version of the Montreal Cognitive Assessment (MoCA-K), IADL was measured using the Korean Instrumental Activities of Daily Living (K-IADL) scale, and digital literacy was evaluated using an 11-item dichotomous scale. Data were analyzed using descriptive statistics, Pearson’s correlation analysis, and hierarchical regression analysis. The moderating effect of digital literacy was tested using the PROCESS macro. Results: Cognitive function was positively correlated with digital literacy (r = 0.56, p < 0.001) and IADL (r = 0.26, p < 0.001), and digital literacy was also positively correlated with IADL (r = 0.25, p < 0.001). In the regression analysis, cognitive function significantly predicted IADL (B = 0.11, p = 0.004), but this effect became non-significant after including digital literacy in the model. A significant moderating effect of digital literacy was observed (B = −0.03, p < 0.001). Conditional effects analysis revealed that cognitive function significantly influenced IADL only among older adults with low levels of digital literacy (B = 0.12, p = 0.005), whereas no significant effect was found at moderate or high levels of digital literacy. Conclusions: Digital literacy significantly moderates the relationship between cognitive function and ADL among community-dwelling older adults. These findings suggest that digital literacy may function as a compensatory mechanism that mitigates the impact of cognitive decline on daily functioning. Enhancing digital literacy may represent an effective strategy to promote functional independence and support aging in place in an increasingly digital society.