Health Insurance Systems in South Korea

In South Korea, the NHI system was introduced in 1977, and by July 1989, the entire population was covered [23]. In the past, NHI in South Korea had multiple insurance societies that covered employees and self-employed individuals separately. In 2000, however, all insurance societies were merged into a single-payer system. The NHI program covers almost 98% of the total population, which in 2014 numbered approximately 50 million people [24]. This system has been maintained until the present. The NHI service is divided into the NHI program and the MA program. The MA program is a public assistance program for low-income people who are recipients of the National Basic Livelihood Security System as part of social welfare programs, which is comparable to the Medicaid program in the United States [25]. Beneficiaries of the MA program are divided into 2 categories, types 1 and 2, based on their inability to work (including those younger than 18 years or older than 65 years and those who are disabled) and their ability to work, respectively [26]. The NHI program is divided into employed and self-employed insured groups. The insurance premium for employed and insured individuals is determined according to income and is paid by the employer. The insurance premium for self-employed individuals is based on household income, property, income, vehicles owned, age, and sex [27]. In 2020, the MA program covered 2.9% of the population, while the NHI program covered 97.1% [28]. Since the NHI service conducts compulsory collection from insured individuals in accordance with the law, the citizens of South Korea are obligated to pay insurance premiums [29].

The NHI service data include patient demographics, general specifications (eg, department, date of visit, and state), in-hospital treatment (eg, medical expenses, prescription fees, examination fees, procedure codes, and operation codes), out-of-hospital prescriptions, diagnoses, death records, and socioeconomic variables such as income decile [27,28]. Cosmetic surgery and unproven therapies are not covered by insurance [29]. The greatest value of these data is that they encompass practically the entire population, making them the closest to real-world data, which are referred to as big data [28]. These government-run national health care claims data are available to researchers for public research purposes [30]. They enable researchers to investigate all prescriptions, procedures, and operations performed by domestic medical institutions [31,32].