BACKGROUND Cost sharing, including copayment and coinsurance, is often used to contain medical expenditure by decreasing unnecessary or excessive use of healthcare resources. Previous studies in Japan have reported the effects of a coinsurance rate reduction for healthcare from 30 to 10% on the demand for healthcare among 70-74-year-old individuals. However, the coinsurance rate for this age group has recently increased from 10 to 20%. This study aimed to estimate the economic impact of coinsurance rate revision on healthcare resource utilization. METHODS We collected claims data from beneficiaries of the municipality National Health Insurance and the Japanese Health Insurance Association in Fukuoka Prefecture. We categorized subjects born between March 2, 1944 and April 1, 1944 into the 20% coinsurance rate reduction group and those born between April 2, 1944 and May 1, 1944 into the 10% reduction group. An interrupted time-series analysis for multiple groups was employed to compare healthcare resource utilization trends before and after coinsurance rate reduction at 70 years. RESULTS The 10% coinsurance rate reduction led to a significant increase in healthcare expenditure for outpatient care. The 20% reduction group showed a significantly sharper increase in healthcare expenditure for outpatient care than the 10% reduction group. Similarly, the 10% coinsurance group significantly increased in the number of ambulatory visits. The 20% coinsurance rate reduction group had more frequent ambulatory care visits than the 10% reduction group. CONCLUSIONS These results suggest that increasing the coinsurance rate among the elderly would reduce outpatient healthcare resource utilization; however, it would not necessarily reduce overall healthcare resource utilization.

中文翻译：

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2014 年老年人共同保险费率修订对日本医疗资源利用的影响。

背景技术成本分摊，包括共付额和共同保险，通常通过减少或过度使用医疗保健资源来控制医疗支出。日本之前的研究报告了将医疗保健的共同保险费率从 30% 降低到 10% 对 70-74 岁人群的医疗保健需求的影响。然而，这个年龄段的共同保险费率最近从 10% 增加到 20%。本研究旨在评估共同保险费率修订对医疗资源利用的经济影响。方法 我们从福冈县的市政国民健康保险和日本健康保险协会的受益人那里收集了索赔数据。我们对出生于 1944 年 3 月 2 日至 4 月 1 日之间的受试者进行分类，1944 年分入 20% 共同保险费率降低组，1944 年 4 月 2 日至 1944 年 5 月 1 日之间出生的人分入 10% 降低率组。采用多组间断时间序列分析来比较 70 年共同保险费率降低前后的医疗资源利用趋势。结果 10% 的共同保险费率降低导致门诊医疗保健支出显着增加。与减少 10% 的组相比，减少 20% 的组显示出门诊医疗保健支出的显着增加。同样，10% 共同保险组的门诊就诊次数显着增加。与降低 10% 的共同保险费率降低组相比，降低 20% 的共同保险费率组的门诊就诊频率更高。结论 这些结果表明，提高老年人的共同保险率会降低门诊医疗资源的利用率；然而，它不会降低整体医疗资源的利用率。