Kupor S A, Liu Y C, Lee J, Yoshikawa A
Comparative Health Care Policy Research Project, Asia/Pacific Research Center, Stanford University, CA 94305, USA.
Int J Health Serv. 1995;25(2):295-312. doi: 10.2190/CU5H-CNQ9-HUW6-993F.
This study uses cross-sectional data from Japan's 47 prefectures covering subscribers to Japan's National Health Insurance system to analyze the effects of income and copayment levels on the utilization of medical care. Multivariate regression models were run for the years 1984 and 1989, with the utilization ratio (number of health insurance claims per 100 insurance subscribers) for total, inpatient, outpatient, and dental services as the dependent variable. Independent variables included copayment per patient day, deflated per capita income, population density, percentage of subscribers over age 65, number of beds and clinics per 1,000 persons, and number of doctors and dentists per 1,000 persons. The data were then stratified according to per capita income and percentage of insurance subscribers over the age of 65 in each prefecture. The copayment amount exhibited a small, but significant negative effect on the utilization of all medical services. Utilization of outpatient care was most sensitive to the copayment rate. The per capita income stratification models revealed the greatest copayment effect on inpatient care for the lowest income group. The results of the age stratification models support popular notions about the use of hospitals by the elderly as substitutes for elderly care facilities. The effects of copayments and income vary not only among the type of medical care (inpatient, outpatient, and dental) but also among the income and age stratifications of groups in the National Health Insurance system.
本研究使用来自日本47个都道府县的横断面数据，这些数据涵盖了日本国民健康保险系统的参保者，以分析收入和自付费用水平对医疗服务利用的影响。对1984年和1989年的数据进行了多元回归模型分析，将总医疗服务、住院服务、门诊服务和牙科服务的利用率（每100名保险参保者的健康保险理赔次数）作为因变量。自变量包括每位患者每天的自付费用、经通胀调整后的人均收入、人口密度、65岁以上参保者的百分比、每1000人的病床和诊所数量以及每1000人的医生和牙医数量。然后根据每个都道府县的人均收入和65岁以上保险参保者的百分比对数据进行分层。自付费用金额对所有医疗服务的利用呈现出虽小但显著的负面影响。门诊服务的利用对自付费用率最为敏感。人均收入分层模型显示，自付费用对最低收入群体的住院护理影响最大。年龄分层模型的结果支持了关于老年人使用医院替代老年护理设施的普遍观点。自付费用和收入的影响不仅在医疗服务类型（住院、门诊和牙科）之间有所不同，而且在国民健康保险系统中不同群体的收入和年龄分层之间也有所不同。
