社会医疗保险、疾病异质性和医疗费用

Social Health Insurance,Heterogeneity of Disease and Medical Expenditures

不同社会医疗保险覆盖的居民在医疗服务及费用方面存在较大差距是我国医疗资源配置不平衡的突出表现。本文利用详尽的住院患者与医疗机构匹配的微观数据,分析了城镇职工基本医疗保险(城职保)和城乡居民基本医疗保险(城乡保)患者花费的差别,及其受疾病种类异质性的影响。在控制疾病种类、患者个人特征和医疗机构等基本特征后,回归结果显示城职保患者的医疗总花费平均显著高于城乡保患者的医疗总花费。用于测量疾病种类异质性程度的疾病总花费变异系数(CV)每增加一个单位,花费差别会增加6.6%—12.8%。其中药品费和检查费在不同保险患者之间的差别受疾病种类异质性的影响较大,而相对固定的诊疗费用差异受到的影响较小。总体而言,疾病种类的异质性会导致医院对不同保险患者收取不同的医疗费用,异质性越大的疾病医疗费用差别就越大。因此,政府应加快推动社会医疗保险支付方式改革,加大监督药品使用和检查项目的力度,从而使医疗资源的配置更加有效。

The Chinese government has expedited healthcare sector reforms over the last two decades.National healthcare expenditures and the total number of beneficiaries of social medical insurance programs have both grown dramatically.National healthcare expenditures reached 5 trillion RMB,6.2%of China's GDP,by the end of 2017.Over 95%of the country's population is covered by one of two social medical insurance programs:Urban Employee Basic Medical Insurance(UEBMI)and Urban Resident Basic Medical Insurance(URBMI).The rapid growth in health care expenditures has resulted in considerable financial pressure for both central and local governments.It has therefore become increasingly important for researchers and policy makers to have a comprehensive understanding of the effects of different medical insurance programs on health expenditures.In this paper,we empirically analyze whether the differences in expenditures between enrollees of UEBMI and URBMI are caused by the type of insurance program they are enrolled in and the degree of heterogeneity of diseases they were treated for.We do this using a detailed micro-level data set of patients and hospitals from the city of Chengdu.UEBMI is a mandatory program that covers people who are currently employed or retired employees.URBMI is a voluntary program that covers the unemployed population,including children and students.Both programs are administered at the city level.They mainly cover inpatient expenses and some chronic conditions.The reimbursement method largely takes the form of a traditional fee for service;however,the two programs'reimbursement rates are very different.The nominal reimbursement rate is 85%for UEBMI enrollees and only 50%-65%for URBMI participants if they are treated in tertiary hospitals in the city.Numerous studies examine the impact of medical insurance programs on patients'expenditures and induced demand in China.Far fewer studies analyze the differential impact of UEBMI and URBMI on medical expenditures and induced demand.Our paper makes three contributions.First,we use a large administrative data set that includes a 10%random inpatient sample of over 300,000 patients between 2011 and 2013.The data set contains detailed and accurate information on patients and hospitals:it includes insurance status,diagnosis,expenditures,length of stay,copayment,and hospital ownership.Second,we calculate the coefficient of variation(CV)of a patient's total expenditures for each disease type(ICD-10)as an indicator of the degree of disease heterogeneity.We assume that the larger a disease's CV,the more heterogeneous the patients.It is easier for doctors and hospitals to price-discriminate against these patients by inducing demand.Doctors can more easily take advantage of information asymmetry when treating patients who are more heterogeneous.Third,we find that drug and checkup expenditures are affected more by CV than diagnosis and treatment expenditures because diagnosis and treatment procedures are relatively fixed.When we control for ICD code and patient and hospital characteristics,our empirical results from OLS and IV estimates show that the medical expenditures of patients covered by UEBMI are 18%higher than that of patients covered by URBMI,which is statistically significant at 1%.For a one-unit increase in CV,UEMBI patients pay 6.6%to 12.8%more than URBMI patients.Our results also indicate that CV has a greater effect on drug and checkup expenditures than on diagnosis and treatment expenditures.In conclusion,the degree of heterogeneity of disease enables doctors to prescribe different medical services to patients covered by different insurance programs.The larger the heterogeneity,the greater the difference in expenditures between UEBMI and URBMI patients.The policy implication is that the Chinese government should expedite the reform of social insurance programs'reimbursement methods to allocate medical resources more efficiently in the future.