The Effect of the Degree of Competition of the Hospital Market Regions on Clinic's Rate of Antibiotics Prescription

병원시장지역 내 경쟁 정도가 의원급 의료기관의 항생제 처방률에 미치는 영향

The rate of antibiotics prescription for an acute airway infection significantly varies depending upon the diagnosis type, specialty, and the location of the hospital along with many other related factors. The objective of this study is to empirically investigate the possible relationship between the antibiotics prescription rates for an acute airway infection and the degree of competition in the hospital market regions of mainly the providers of primary medical care services such as clinics, internal medicines, pediatrics and otorhinolaryngology department. Using the data from Health Insurance Review and Assessment Service (HIRA) regarding the hospitals' antibiotics prescription rates for the acute airway infection and controlling for selected variables of demand and supply sectors, this study tries to figure out that the degree of competition in the hospital market, regardless of what type of competition indexes we employed, has a statistically significant effect on the variations of antibiotics prescription rate of the clinics in local areas. This result implies that as an economic consideration itself, the change in the degree of competition in the hospital market can play a crucial role influencing the treatment behaviors of the medical doctors. More specifically, this study reveals that as the degree of competition increases the antibiotics prescription rate goes up. This result means that if the market becomes more competitive in a specific region so that it might cause a reduction in doctor's income, doctors with rational decision-making process, recognize that the benefit created from inducing patients' seemingly unnecessary demand for medical care (income effect) would be higher than the costs associated with sustaining their targeted income (substitution effect). It is because that the doctors are more likely to prescribe antibiotics which create relatively higher margins than other medical care services in order to sustain their targeted income when the hospital market competition becomes tighter. Even though this study empirically confirms that antibiotics prescription can be affected by the economic incentives, it still raises following issues as limitations of the study: first issue is about the representativeness of the hospital regions segregated for this study, which might be weak in explaining whether these regions are mutually exclusive in reality. Patients actually consider the quality of services, transportation cost, time costs, and any other related factors choosing the doctors or hospitals, and in that sense, this study rules out 'border-crossing' in using the medical care services. Second issue arises in capturing the data of antibiotics prescription rate. Since we use the average rate for each medical institution, we cannot figure out the average rate for each patient so that we are not able to control for the variation of patients' medical conditions. It is because of the unavailability of data regarding each patient's medical condition from HIRA. Thirdly, since this study mainly analyzes the medical institutions providing primary care such as clinics, internal medicines, pediatrics, and otorhinolaryngology department, it is skeptical of whether those institutions can represent the hospital market in respective regions and truly reflect the degree of competition. It needs to extend the study areas and disease types as well as any micro data for future studies.

급성상기도감염증에 대한 항생제 처방률은 의료기관의 유형, 표시과목, 의료기관이 위치한 지역 등 여러 요인에 따라 차이를 보인다. 본 연구는 1차 의료기관인 의원들 중 내과, 소아과, 이비인후과 의원의 급성상기도감염증에 대한 항생제 처방률에 환자의 특성과 같은 의학적 요인이 아닌 의원의 수입과 밀접한 관계가 있는 의원 수의 변화(경쟁 정도의 변화)와 같은 경제적 요인이 미치는 영향을 실증 분석하였다. 2006년 건강보험심사평가원에서 발표한 전국 각 의료기관의 급성상기도감염증에 대한 항생제 처방률을 주 자료원으로 하여, 경쟁지수를 두 가지 형태로 정의하고 수요 측면을 나타내는 변수와 공급 측면을 나타내는 변수를 통제변수로 선정하여 회귀분석을 실시한 결과 경쟁지수를 어떤 형태로 정의하든, 의원이 위치한 지역의 경쟁정도는 의사들의 항생제 처방률에 통계적으로 유의한 영향을 미친 것으로 분석되었다. 이러한 결과는 시장지역 내 경쟁 정도의 변화와 같은 경제적 요인이 의사들의 처방행태에 영향을 미치는 요인 중 하나라고 해석할 수 있다. 아울러 인과관계의 방향과 관련하여, 의사가 진료하는 지역의 경쟁 정도가 높아질수록 항생제 처방률이 통계적으로 유의하게 높아지는 것으로 나타났다. 이러한 결과는 의사의 진료수입 감소를 초래할 것으로 예상되는 시장환경의 변화에 대해 자신의 진료수입을 예전상태로 보전하기 위해 불필요한 의료서비스 소비를 유도해서 얻는 편익(소득효과)이 이를 위해 자신이 지불해야 할 비용(대체효과)보다 크기 때문에 항생제 처방률을 증가시킨 것으로 해석할 수 있으며, 또한 경제적 유인체계의 변화에 대하여 의사의 진료행태가 영향을 받을 수 있음을 실증적으로 뒷받침하는 것으로 이해할 수 있을 것이다.