中文摘要：

以往研究和实践往往主观设定灾难性医疗支出，这有碍医疗保险保障公平性与精准化，从而影响社会整体福利改进。本文发现，医疗自负与收入约束的关系影响医疗服务需求对医疗保险补偿水平的反应敏感度，据此采用我国微观数据建立面板门槛回归模型进行实证分析。结果表明：我国整体灾难性医疗支出标准为家庭年度医疗服务自负金额超过收入的41．21％；低收入、中低收入和中收入组的灾难性医疗支出标准分别为14．20％、32．24％和56．07％，而中高收入和高收入组的可能更高；细分后的总体灾难性医疗支出发生率变化不大，但层级差异更加明显，产生再分配效应，有利于提升社会总体福利。

英文摘要：

Previsous researches and practices tended to set catastrophic medical expenditure standards subjectively, which hindered the equitability and precision of social healthcare security, and in turn, the enhancement of overall social welfare. The paper found that the relationship between medical out-of-pocket payment and income constraint impacted medical demands~sensitivity to medical insurance compensation level. Based on this finding, the paper built a threshold panel model using micro health care utilization data. The results showed that：the overall boundary standard of catastrophic health expenditure in China should be 41.21% ;it could be subdivided into 14.20%, 32.24% and 56.07% for low, lower middle and middle income households, and even higher for higher middle and high income households ; the overall incidence of catastrophic health expenditure after subdivision had little change, but the gap between different income levels was more obvious, resulting in a redistribution effect, which helped to enhance the overall social welfare.