Dr. Hyun Sook Lee

Kongju National University, South Korea

Abstract Title: Household Type Modifies the Income–Health Gradient in Health-Related Quality of Life Among Korean Adults: A Cross-Sectional Analysis of the 2024 Korea Community Health Survey

Biography: Dr. Hyun-Sook Lee is an Associate Professor in the Department of Health Administration at Kongju National University, South Korea. She earned her Ph.D. in Public Health from Yonsei University. Her professional expertise includes health administration, medical marketing, and community-based health program management. She has served as an evaluator and consultant for numerous government organizations, including the Ministry of Health and Welfare and the Korea Disease Control and Prevention Agency. Her research focuses on health disparities, mental health among vulnerable populations, and the social determinants of health.

Research Interest: Objectives: This study examined differences in health-related quality of life (HRQoL), measured by the EQ-5D index, according to income level using data from the 2024 Korea Community Health Survey, and investigated whether the income–health gradient varies by household type Methods: The study included 227,687 adults aged ?19 years who participated in the 2024 survey. Household income was equivalized using the OECD-modified equivalence scale and categorized into quintiles. HRQoL was assessed using the EQ-5D index calculated with the Korean value set. Survey-weighted multivariable linear regression analyses were conducted to account for the complex sampling design. Sociodemographic characteristics, health behaviors, mental health, and regional factors were sequentially adjusted. The interaction between income level and household type was evaluated using the Wald test. Results: Higher income levels were significantly associated with higher EQ-5D scores, demonstrating a clear linear trend (p for trend <0.001). In the fully adjusted interaction model, compared with the lowest income quintile (Q1), Q2 (?=0.013; 95% CI, 0.011–0.015), Q3 (?=0.013; 95% CI, 0.011–0.014), Q4 (?=0.012; 95% CI, 0.010–0.014), and Q5 (?=0.011; 95% CI, 0.009–0.013) were all significantly associated with higher EQ-5D scores (all p<0.001). Single-person households had lower EQ-5D scores than multi-person households (?=?0.010; 95% CI, ?0.013 to ?0.007). The income–household type interaction was statistically significant (p for interaction <0.001), with greater vulnerability observed among low-income single-person households. Conclusions: A clear income–health gradient was identified among Korean adults, and inequality was more pronounced in single-person households. Policies promoting health equity should prioritize low-income single-person households.