Comparison of out-of-pocket expenditure and catastrophic health expenditure for severe disease by the health security system: based on end-stage renal disease in South Korea.

Background: Korea's health security system named the National Health Insurance and Medical Aid has revolutionized the nation's mandatory health insurance and continues to reduce excessive copayments. However, few studies have examined healthcare utilization and expenditure by the health security system for severe diseases. This study looked at reverse discrimination regarding end-stage renal disease by the National Health Insurance and Medical Aid.

Methods: A total of 305 subjects were diagnosed with end-stage renal disease in the Korea Health Panel from 2008 to 2013. Chi-square, t-test, and ANCOVA were conducted to identify the healthcare utilization rate, out-of-pocket expenditure, and the prevalence of catastrophic expenditure. Mixed effect panel analysis was used to evaluate total out-of-pocket expenditure by the National Health Insurance and Medical Aid over a 6-year period.

Results: There were no significant differences in the healthcare utilization rate for emergency room visits, admissions, or outpatient department visits between the National Health Insurance and Medical Aid because these healthcare services were essential for individuals with serious diseases, such as end-stage renal disease. Meanwhile, each out-of-pocket expenditure for an admission and the outpatient department by the National Health Insurance was 2.6 and 3.1 times higher than that of Medical Aid (P < 0.05). The total out-of-pocket expenditure, including that for emergency room visits, admission, outpatient department visits, and prescribed drugs, was 2.9 times higher for the National Health Insurance than Medical Aid (P < 0.001). Over a 6-year period, in terms of total of out-of-pocket expenditure, subjects with the National Health Insurance spent more than those with Medical Aid (P < 0.01). If the total household income decile was less than the median and subjects were covered by the National Health Insurance, the catastrophic health expenditure rate was 92.2%, but it was only 58.8% for Medical Aid (P < 0.001).

Conclusion: Individuals with serious diseases, such as end-stage renal disease, can be faced with reverse discrimination depending on the type of insurance that is provided by the health security system. It is necessary to consider individuals who have National Health Insurance but are still poor.