Development and validation of the Health Literacy Index for the Community for the Korean National Health and Nutrition and Examination Survey

OBJECTIVES: We developed and validated the Health Literacy Index for the Community (HLIC) to assess the health literacy of the Korean population within the framework of the Korean National Health and Nutrition and Examination Survey. METHODS: The HLIC was developed through (1) defining the conceptual framework and generating the item pool and (2) finalizing the items and identifying the cut-off value. Interviews were conducted to examine items’ face validity, and a cross-sectional survey was performed to analyze the item-response theory and Rasch models to investigate the instrument’s psychometric properties. RESULTS: In this study of 1,041 participants, most had no difficulty understanding health information; however, 67.9% struggled to assess the reliability of health information from the Internet or media. A 4-factor structure was identified through factor analysis, leading to the exclusion of some items. This resulted in 10 items across 4 domains: (1) disease prevention, (2) health promotion, (3) health care, and (4) technology and resources. The HLIC demonstrated good internal consistency, with a Cronbach’s α of 0.87. It also showed high test-retest reliability and correlations with other health literacy instruments. A socio-demographic analysis of the HLIC revealed disparities in health literacy across various age groups, education levels, and income brackets. CONCLUSIONS: The HLIC was developed to systematically measure health literacy in Korea’s general population. Its simplicity and conciseness ensure reliability and validity and improve its accessibility, making it particularly suitable for the broader Korean population, including those with lower literacy levels.