Monthly 제 23 호 건강보험가입과의료이용행태 이정택연구위원 건강보험과의료이용간의관계를살펴본연구들은대체적으로건강보험가입이외래및입원서비스이용을증가시키는것으로보고하고있음. 외래및입원서비스이용과는달리건강보험가입이응급실 (ER) 이용에미치는영향에대한선행연구들은결과에차이가발생함. 정책수혜를받는집단간에도이질성 (Heterogeneous) 으로인하여응급실이용에차이가발생하는것으로보임. 도덕적해이의정도는건강보험의정책수혜를받는집단내에서도차이가발생할뿐만아니라, 건강보험의보장성정도혹은정책수혜의규모등주어진환경에따라그영향에차이가발생하는것으로평가됨. 따라서건강보험이의료이용에미치는영향을고려할때, 건강보험의정책수혜여부뿐만아니라정책수혜자집단간의차이와정책수혜의정도등제반여건을다각도로고려할필요가있음 요약 건강보험과의료이용간의관계를살펴본연구들은대체적으로건강보험의가입이외래및입원서비스이용을증가시키는것으로보고하고있음 Card et al.(2008) 은 65세이후노인에게제공하는메디케어 (Medicare) 로인해 65세이전보다이후에외래및입원이용이증가하였음을보고하고있으며, Dafny and Gruber(2005) 는메디케이드 (Medicaid) 1) 자격요건의확대로인해입원이증가함을보임 Finkelstein et al.(2012) 은오레건 (Oregon) 주의메디케이드확대로인해의료서비스의이용이증가하였으며, 의료서비스이용확대는주민의건강증진에도움이된다고주장함한편, Chen et al.(2007) 은대만의국민건강보험의도입으로인한의료서비스보장성확대로외래및입원이용이저소득집단에서크게증가함을보임 1) 미국의연방정부와주정부가공동으로운영하며 65 세미만의저소득층과장애인을위한의료보조제도임. 2008 년기준으로 4,900 만명에게의료혜택을주고있으나연방정부와주정부예산에부담으로작용함에따라메디케이디비용을보험회사에매달일정금액씩제공하고보험회사는보험을제공함 15
건강보험가입이의료이용에미치는영향을파악하기위해사용하는연구방법중가장효과적인방법은개인에게건강보험을무작위 (randomization) 로할당하는실험방식임역선택 2) 과도덕적해이 3) 로인한의료이용을구분할수있어야건강보험가입이의료이용에미치는영향을파악할수있으며, 무작위할당실험방식은이를위한효과적인방법임건강보험을무작위로할당하는실험방식의대표적인사례는 1970년대중반미국랜드 (RAND) 연구소가약 6,000명의표본에건강보험을할당하여건강보험의가입이의료이용에미치는영향을살펴본연구임 4) 2008년오레곤 (Oregon) 주는메디케이드 (Medicaid) 혜택을받지못하는저소득층을대상으로추첨 (lottery) 을통해약 9만명의신청자중 1만명에게메디케이드를제공하였고, 이를이용해 Finkelstein et al.(2012) 은건강보험의가입과의료이용간의관계를살펴봄 건강보험을무작위로할당하는실험방식은비용이많이들기때문에, 대안으로건강보험에대한정책변화로인한개인들의건강보험보장변화를이용하는준실험적 (quasi-experiment) 방식을이용함메디케어가 65세이후제공되는것을이용하여 65세전후사람들의의료서비스수요변화를살펴볼수있음 5) 1990년대미국에서메디케이드자격요건확대라는외생적인정책변화를이용하여정책변화전후의정책수혜자와비수혜자의의료이용차이를살펴봄 6) 2006년메사추세츠 (Massachusettes) 주의건강보험개혁법과 2014년연방차원의건강보험개혁법인오바마케어 (Obamacare) 의건강보험의무가입정책을이용하여가입자와비가입자의의료이용의차이를살펴볼수있음 7) 무작위할당실험방식이나준실험적방식을이용하여건강보험의가입이외래및입원서비스이용에 미치는영향을살펴본연구들과는달리건강보험의가입이응급실 (ER) 이용에미치는영향에대한선 행연구들은결과에차이가발생함 2) 예를들면민영건강보험의경우가입심사과정을통해건강이나쁜사람이건강보험에가입하지못하고, 상대적으로건강한사람들만이민영건강보험의가입이가능한경우건강보험이의료이용에미치는영향은과소추정될수있음 3) 건강보험의가입은의료소비자에게의료서비스가격하락을의미하기때문에낮은가격에더많은의료서비스를소비하는도덕적해이가발생할수있음 4) Lohr et al.(1986) 5) Card et al.(2008) 6) Finkelstein et al.(2012) 7) Chen et al.(2011); Kolstad and Kowalski(2012); Miller(2012); Smulowitz et al.(2011) 16
건강보험가입자이든미가입자이든상관없이응급실을이용할수있고, 상대적으로미가입자는응급실을통해의료서비스를이용하는경우가많음 2006년메사추세츠주건강보험개혁을이용하여건강보험과응급실이용의관계를살펴본연구들 (Chen et al. 2011; Kolstad and Kowalski 2012; Miller 2012; Smulowitz et al. 2011) 은건강보험가입의무화로인해응급실사용이오히려줄어들거나또는변화가없다고보고함 Taubman et al.(2014) 은오레건주메디케이드실험에서건강보험을새롭게가입하는사람들의도덕적해이로인하여응급실이용이증가한것으로보고함 선행연구들의결과에차이가발생하는이유를 Kowalski(2018) 는건강보험정책변화로건강보험가입이가능한집단들의특성들이달라졌기때문에응급실이용에차이가발생하는것으로설명함실제로추첨을통해메디케이드를제공받는집단은 Never taker, Always taker, Complier 그룹으로구분됨 - Never taker 그룹은당첨과상관없이당첨전후모두메디케이드를가입신청하지않는그룹임 - Always taker 그룹은당첨과상관없이당첨전후모두가입을신청하는그룹임 - Complier 그룹은당첨전에는가입을신청하지않고, 당첨후에가입을신청하는그룹임 Kowalski(2018. 5) 는 Complier 그룹과비교하여 Always taker 그룹은평균적으로응급실이용이많으며, Never taker 그룹은평균적으로응급실이용이적음을주장함 - 메디케이드와같은건강보험의가입으로인한도덕적해이는정책수혜를받는집단내에서도차이가발생함을알수있음 Taubman et al.(2014) 의결과는정책시행이전에는메디케이드에가입하지않았으나시행이후가입할그룹 (complier) 에만해당되는결과로서메디케이드가입으로인한응급실이용증대효과를과대추정할수있음메사추세츠주건강보험가입의무화조치를이용하여건강보험과응급실이용의관계를살펴본연구는 Complier, Always taker, Never taker 그룹을구분하지않고모두고려한것임 - 건강보험가입의무화로오히려응급실이용이줄어든다는연구결과들은 Never taker 그룹의영향이반영된것으로판단될수있음 도덕적해이의정도는건강보험의정책수혜를받는집단내에서도차이가발생할뿐만아니라, 건강보 험의보장성정도혹은정책수혜의규모등주어진환경에따라그영향에차이가발생하는것으로 평가됨 17
오레건주는메디케이드만을확대한반면, 메사추세츠주의건강보험개혁은메디케이드를포함한모든건강보험의보장성확대정책이었음오레건주의메디케이드확대는그정책실험에참여한사람들만을대상으로한반면, 메사추세츠주는주차원의전반적인건강보험확대정책인점에서차이가발생함 따라서건강보험이의료이용에미치는영향을고려할때, 건강보험의정책수혜여부뿐만아니라정책 수혜자집단간의차이와정책수혜의정도등제반여건을다각도로고려할필요가있음 참고문헌 Card, D., Dobkin, C., & Maestas, N.(2008), The impact of nearly universal insurance coverage on health care utilization: Evidence from medicare The American Economic Review, 98(5), p. 2242 Chen, L., Yip, W., Chang, MC., Lin, HS., Lee, SD., Chiu, YL., and Lin, YH.(2007), The Effects of Taiwan s National Health Insurance on Access and Health Status of the Elderly Health Economics, 16, pp. 223~242 Dafny, L., & Gruber, J.(2005), Public insurance and child hospitalizations: Access and efficiency effects Journal of Public Economics, 89(1), pp. 109~129 Finkelstein, A., Taubman, S., Wright, B., Bernstein, M., Gruber, J., Newhouse, J. P., & Oregon Health Study Group(2012), The Oregon health insurance experiment: Evidence from the first year The Quarterly Journal of Economics, 127(3), pp. 1057~1106 Kolstad, J. T.,& Kowalski,A. E.(2012), The impact of health care reform on hospital and preventive care: Evidence from Massachusetts Journal of Public Economics, 96(11), pp. 909~929 Kowalski, A. E.(2018), Extrapolation using Selection and Moral Hazard Heterogeneity from within the Oregon Health Insurance Experiment National Bureau of Economic Research Lohr, K. N., Brook, R. H., Kamberg, C. J., Goldberg, G. A., Leibowitz, A., Keesey, J.,... &Newhouse, J. P.(1986), Use of medical care in the RAND Health Insurance Experiment: diagnosis-and service-specific analyses in a randomized controlled trial Medical care, 24(9), pp. S1~S87 Miller, S.(2012), The effect of insurance on emergency room visits: An analysis of the 2006 Massachusetts health reform Journal of Public Economics, 96(11), pp. 893~908 Smulowitz, P. B., Lipton, R., Wharam, J. F., Adelman, L., Weiner, S. G., Burke, L.,... &Liu, B.(2011), Emergency department utilization after the implementation of Massachusetts health reform Annals of emergency medicine, 58(3), pp. 225~234 18
Taubman, S. L., Allen, H. L., Wright, B. J., Baicker, K., &Finkelstein, A. N.(2014), Medicaid increases emergency-department use: evidence from Oregon s Health Insurance Experiment Science, 343(6168), pp. 263~268 19