Unmet Healthcare Needs, Catastrophic Health Expenditure, and Health in South Korea's Universal Healthcare System: Progression Towards Improving Equity by NHI Type and Income Level.

This study examined the effects of healthcare inequality on personal health. It aimed to determine how health insurance type and income level influence catastrophic health expenditure and unmet healthcare needs among South Koreans. Unbalanced Korean Health Panel data from 2011 to 2015, including 33,374 adults, were used. A time-trend and panel regression analysis were performed. The first to identify changes in the main variables and, the second, mediating effects of unmet healthcare needs and catastrophic health expenditure on the relationship between health insurance type, income level, and health status. The independent variables were: high-, middle-, low-income employee insured, high-, middle-, low-income self-employed insured, and medical aid. The dependent variable was health status, and the mediators were unmet needs and catastrophic health expenditure. The medical aid beneficiaries and low-income self-employed insured groups demonstrated a higher probability of reporting poor health status than the high-income, insured group (15.6%, 2.2%, and 2.3%, respectively). Participants who experienced unmet healthcare needs or catastrophic health expenditure were 10.7% and 5.6% higher probability of reporting poor health, respectively (Sobel test: p < 0.001). National policy reforms could improve healthcare equality by integrating insurance premiums based on income among private-sector employees and self-employed individuals within the health insurance network.