민간의료보험 가입이 의료이용에 미치는 영향

Effects of Private Insurance on Medical Expenditure

민간보험은 공적보험과 보완적인 관계를 형성함에도 불구하고 우리나라의 민간보험은 소득계층에 따른 접근성 차이로 인한 사회적 불평등, 도덕적 해이로 인한 공적보험 재정악화 등의 우려를 낳고 있다. 그러나 이에 관한 실증적 분석은 그간 이루어지지 못하여 정책적인 방향을 정립하는 데 장애가 되어 왔다. 본 연구는 건강보험공단, 심사평가원, 민간보험사, 행정자치부 주민등록세대정보 등의 관련 정보를 종합하여 이에 대한 실증분석을 시도했다. 그 결과, 우리나라의 민간보험 가입률은 전 국민의 64%에 달하고 있으며, 고소득층과 저소득층 간에 민간보험 가입률의 차이가 나타나지 않았다. 이는 공적보험의 보장성이 미흡한 상황에서 저소득층 역시 갑작스런 의료지출에 대비하고 있으며, 민간보험이 의료접근성의 계층화를 초래하지 않고 있다는 것을 시사한다. 또한 민간보험 가입자는 평균적으로 미가입자에 비해 의료이용량이 높지 않았으며, Two-Part Model을 통해 다양한 변수를 통제했을 경우에도 동일한 결과가 나타났다. 연령대에 따른 차이로 미루어 이러한 결과는 노동시장과 연관된 한시적인 성격일 것으로 추측되나, 현재로서는 민간보험 가입에 따른 도덕적 해이가 강하게 나타나고 있다는 근거는 발견되지 않았다.

Nearly all Koreans are insured through National Health Insurance(NHI). While NHI coverage is nearly universal, it is not complete. Coverage is largely limited to minimal level of hospital and physician expenses, and copayments are required in each case. As a result, Korea's public insurance system covers roughly 50% of overall individual health expenditures, and the remaining 50% consists of copayments for basic services, spending on services that are either not covered or poorly covered by the public system. In response to these gaps in the public system, 64% of the Korean population has supplemental private health insurance. Expansion of private health insurance raises negative externality issue. Like public financing schemes in other countries, the Korean system imposes cost-sharing on patients as a strategy for controlling utilization. Because most insurance policies reimburse patients for their out-of-pocket payments, supplemental insurance is likely to negate the impact of the policy, raising both total and public sector health spending. So far, most empirical analysis of supplemental health insurance to date has focused on the US Medigap programme. It is found that those with supplements apparently consume more health care. Two reasons for higher health care consumption by those with supplements suggest themselves. One is the moral hazard effect: by eliminating copayments and deductibles, supplements reduce the marginal price of care and induce additional consumption. The other explanation is that supplements are purchased by those who anticipate high health expenditures - adverse effect. The main issue addressed has been the separation of the moral hazard effect from the adverse selection one. The general conclusion is that the evidence on adverse selection based on observable variables is mixed. This article investigates the extent to which private supplementary insurance affect use of health care services by public health insurance enrollees, using Korean administrative data and private supplements related data collected through all relevant private insurance companies. I applied a multivariate two-part model to analyze the effects of various types of supplements on the likelihood and level of public health insurance spending and estimated marginal effects of supplements. Separate models were estimated for inpatients and outpatients in public insurance spending. The first part of the model estimated the likelihood of positive spending using probit regression, and the second part estimated the log of spending for those with positive spending. Use of a detailed information of individuals' public health insurance from administration data and of private insurance status from insurance companies made it possible to control for health status, the types of supplemental insurance owned by theses individuals, and other factors that explain spending variations across supplemental insurance categories in isolating the effects of supplemental insurance. Data from 2004 to 2006 were used, and this study found that private insurance increased the probability of a physician visit by less than 1 percent and a hospital admission by about 1 percent. However, supplemental insurance was not found to be associated with a bigger health care service utilization. Two-part models of health care utilization and expenditures showed that those without supplemental insurance had higher inpatient and outpatient expenditures than those with supplements, even after controlling for observable differences.