How does health insurance copayment affect the use of medical services and health outcomes

该项目旨在调查健康保险和相关健康政策对健康结果的影响。生活条件综合调查（CSLC）的数据，以便于分析在日本的个人健康结果的健康政策的影响。由于70岁以下和70岁至74岁之间的医疗费用共同支付不同，并且医疗费用的份额在2014年发生了变化，因此70岁的门槛和政策变化提供了自然实验来估计共同保险对健康结果的因果影响。利用2013年和2016年的数据，采用差异中的差异（DID）方法来估计自付费用变化对健康结局的平均治疗效果。结果表明，一般来说，健康保险覆盖率的下降（即，增加共同支付）减少了积极的健康行为。然而，对危险健康行为的影响好坏参半。此外，受教育程度较高的人往往在积极和消极的健康行为方面有更大的改变。此外，与女性相比，男性吸烟量下降幅度较大，但饮酒量显著增加。研究结果对政策制定具有重要意义：通过了解医疗保险覆盖范围对各种健康行为的影响，政策制定者可以制定有针对性的干预措施和策略，以鼓励不同人群的积极行为变化。

This project is aimed at investigating the effects of health insurance and related health policies on health outcomes. The data of Comprehensive Survey of Living Conditions (CSLC) were obtained to facilitate analyzing the health policy impacts on health outcomes of individuals in Japan. Since the co-payment of medical fees differs for those below 70 and between 70 and 74, and the share of medical fees changed in 2014, the threshold at age 70 and policy changes provide natural experiments to estimate the causal effects of coinsurance on health outcomes. By utilizing the data in 2013 and 2016, the method of difference-in-differences (DID) is adopted to estimate the average treatment effects of the change in co-payment on health outcomes. The results indicate that in general, decrease in health insurance coverage (i.e., increase in co-payment) reduces positive health behaviour. However, the impact on risky health behaviour is mixed. Furthermore, people with higher education level tend to have a stronger change in their behaviour for both positive and negative health behaviour. Besides, males have a larger decline in smoking but have a significant increase in alcohol consumption compared to females. The findings of the study have significant implications for policy-making: by understanding the effects of health insurance coverage on various health behaviors, policymakers can develop targeted interventions and strategies to encourage positive behavioral changes in different population segments.