Reliability and Validity of the Korean Version of the Digital Health Literacy Instrument

Abstract

Background: As digital transformation accelerates, individuals increasingly engage with digital health services and online medical resources, and digital health literacy (DHL) becomes increasingly important. While the Digital Health Literacy Instrument (DHLI) has been validated internationally, a Korean version applicable across all adult age groups remains limited. This study develops and validates the Korean DHLI, assessing its reliability and validity for broader applicability among Korean adults. Methods: The DHLI was translated, culturally adapted, and reviewed by expert panels following World Health Organization guidelines. A cross-sectional nationwide web survey was conducted with 524 adults aged 19-69. A follow-up survey was administered to 134 participants after four weeks to assess test-retest reliability. Internal consistency and test-retest reliability were assessed. Construct validity was examined using confirmatory factor analysis (CFA) to determine the most appropriate factor structure in the Korean population. Convergent and discriminant validity were assessed, and hypothesis-testing construct validity was evaluated through correlations with age, health status, and eHealth literacy. Results: The Korean version of the DHLI (K-DHLI) exhibited excellent psychometric properties. Internal consistency was high (alpha = 0.91), and test-retest reliability was deemed acceptable (intraclass correlation coefficient = 0.70). CFA demonstrated a 7-factor model, which showed a superior model fit (chi(2)/degrees of freedom = 2.14, comparative fit index = 0.966, root mean square error of approximation = 0.047) as compared to the 5-factor model. Convergent and discriminant validity were confirmed, with AVE values ranging from 0.7218 to 0.8947 and construct reliability values between 0.8837 and 0.9622. Hypothesis-testing construct validity was supported by hypothesized correlations between K-DHLI scores and age (r = -0.254, P < 0.001), health status (r = 0.252, P < 0.001), and eHealth literacy (r = 0.688, P < 0.001). Conclusion: The K-DHLI is a reliable and valid instrument for assessing DHL in the Korean population. The findings confirm that the 7-factor structure demonstrates superior model fit and further support its applicability across diverse adult groups. This study provides a standardized instrument for assessing DHL in Korea and facilitates its use in national surveys, clinical screening, and research. It may help identify individuals with limited DHL, thereby supporting targeted interventions to reduce health disparities and improve access to care.