To our knowledge, this is the first study to examine the impacts of supplementary PHI on cancer care experienced by Korean patients. Our findings reveal that older, less-educated, poorer, and/or unemployed people with cancer are least likely to be covered by PHI. This raises many concerns with regards to inequity, as these groups of people are generally more vulnerable to severe financial burdens when they are affected by serious illnesses such as cancer. These subjects may elect not to purchase PHI because they cannot afford it. Alternatively, these subjects may have been excluded from PHI. In the absence of a well-equipped underwriting system, premiums are usually determined by age and gender, and payments are fixed regardless of the actual medical bills. Thus, there is no financial incentive for the PHI companies to promote PHI to high-risk populations. Indeed, nearly all patients who are over 60 years of age or have pre-existing conditions are excluded from PHI coverage to avoid adverse selections.
Our findings are consistent with a previous Korean study, which found that younger, highly educated, wealthier, and employed patients were most likely to have PHI coverage . Similar findings have been reported in Taiwan, where PHI serves a supplement to mandatory NHI coverage . The Medigap plan, which provides supplementary insurance to Medicare beneficiaries in the US, is more likely to be purchased by elderly patients who are relatively younger, wealthier, better educated and in better health . Taken together, it is unlikely that supplementary PHI functions as an adequate safety net for vulnerable populations.
Interestingly, most cancer survivors expressed appreciation for the assistance provided by supplementary PHI coverage. This result should be interpreted with caution, as these subjects are the winners of "jackpot" insurance. It has been suggested that supplementary PHI is likely to over-insure (and occasionally underinsure) Korean patients. The average benefits awarded to newly diagnosed cancer patients between 2001 and 2005 were approximately $20,000 USD (i.e., 19 million KRW, with an exchange rate of 900 to 1000 during that period) , while co-payments during the year of diagnosis are often lower than $10,000 USD. This may explain why many cancer survivors perceive PHI as beneficial, and why they are more likely than other patients to pay their own medical bills.
Our findings indicate that, apart from financial independence, PHI does not significantly impact access to health care, patient autonomy or patient satisfaction. Thus, patients with PHI appear to receive similar treatment as those without PHI. This is in contrast to other studies, which have suggested that PHI improves healthcare accessibility [16, 25] and influences quality of care .
Our finding that PHI has no significant beneficial influence on cancer care is somewhat disappointing, because previous studies have consistently shown that PHI increases the utilization and expenditure of healthcare in Korea. Those previous data are indicative of insurance effects or moral hazards, at least in outpatient settings [24, 27, 28]. However, our findings are not surprising when the mechanisms of PHI in Korea are examined more closely. Unlike PHI companies in the US, which provide primary coverage for most of the population and reimburse patients for incurred expenses, PHI companies in Korea do not have access to medical data, and cannot impose regulations on patient care (e.g., with regards to healthcare access, service coverage and quality of care). Thus, our results suggest that expanding PHI coverage will not improve the Korean health care system.
Our study has several limitations. By conducting a retrospective, cross-sectional survey of disease-free survivors of stomach cancer, our results are subject to recall bias and we were unable to assess the patients' experiences during the actual treatment period. Also, patients with advanced disease or recurrence were not included in our analysis, which may have contributed to the relatively high satisfaction rate. Furthermore, a potential selection bias may have resulted from our low response rate (i.e., 52.8%). However, adjustment via the propensity weighting method  showed no significant differences from our original findings (data not shown), suggesting that the respondents adequately represented the entire eligible population. Last, as these data were obtained from a general cancer survivorship survey, we were unable to determine specific details regarding patients' PHI coverage, such as the type of plans and the amount of benefits. However, due to the unique characteristics of PHI in Korea, these data were not required for the interpretation of our results.