Eur J Cancer Care. 2018;e12867. wileyonlinelibrary.com/journal/ecc | 1 of 6 https://doi.org/10.1111/ecc.12867 © 2018 John Wiley & Sons Ltd 1 | INTRODUCTION Cancer is a disease that poses a great burden not only on the pa- tients and their families but also in terms of socioeconomic aspects. As of 2013, the incidence of cancer in Korea was 445.7 per 100,000 persons, and if Koreans live to the average lifespan, they appear to have a 36.6% chance of getting cancer. Mortality due to cancer is 150.8 per 100,000 persons as of 2015, which takes up the biggest portion (27.9%) of the cause of death. In addition, health insurance medical expenditure for cancer in 2015 was 4.9 trillion KRW, which is 8.5% of total health insurance medical expenditures. The govern- ment consistently implemented the insurance guarantee reinforce- ment policy to protect patients with cancer financially and focused on increasing coverage by switching nonpayment items to payment items. However, the health insurance coverage for beneficiaries of the special benefit system for patients with cancer is 72.6%, which indicates that patients cover at least 1/4 of the total health expen- ditures through out-of-pocket payments, and nonpayment out-of- pocket fees is approximately 20% of total health expenditures. As such, cancers result in a great burden of health expenditures and have a significant impact on household income (Berkowitz & Johnson, 1974). The concept of catastrophic health expenditure (CHE) is a typical indicator that measures households’ economic burden. CHE occurs if the household’s health expenditure compared to its economic capacity (ability to pay) exceeds a certain threshold (Wyszewianski, 1986; Xu et al., 2003). This concept measures the eco- nomic burden and loss due to health expenditures, and researchers use it to indirectly evaluate the health security system in terms of its Received: 4 April 2017 | Revised: 4 April 2018 | Accepted: 17 April 2018 DOI: 10.1111/ecc.12867 ORIGINAL ARTICLE Private health insurance and catastrophic health expenditures of households with cancer patients in South Korea Munjae Lee 1 | Kichan Yoon 2 * | Mankyu Choi 3,4 * *These two authors contributed to this work equally. 1 Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Korea 2 Social Security Information Service, Seoul, Korea 3 BK21Plus Program in Public Health Science, Korea University, Seoul, Korea 4 Department of Public Health Science, Graduate School of Korea University, Seoul, Korea Correspondence Kichan Yoon, Social Security Information Service, Seoul, Korea Email: ykichan08@gmail.com Abstract This study examines the effects of private health insurance (PHI) on the incidence of catastrophic health expenditures (CHE) for households with a patient with cancer. This study uses 1-year data from 2013 and households with cancer patients as the unit of research rather than individual household members. The sample thus includes 468 households with members with cancer who also used emergency, outpatient and hospitalisation services. Households with PHI had a lower incidence of CHE for all thresholds than those without did. At the 10% threshold, the incidence became significantly lower, by 0.59 and 0.60 times, respectively, if householders had higher education and income levels. Moreover, the incidence of CHE was higher by 8.71 times if the householders are female, and lower by 0.84 times if the householders did not have a spouse at the 20% threshold. From the analysis of households with cancer patients that hold PHI as the key variable, these households showed a lower inci- dence of CHE than the others did. PHI provides healthcare payments not secured through national health insurance (NHI) and protects households from health expen- ditures, thereby complementing NHI to a certain degree. KEYWORDS cancer patients, catastrophic health expenditure, healthcare, Korea health panel, private health insurance, South Korea