不合理入院是指在不需要住院治疗的情况下选择住院治疗的情况。本项目对不合理入院中各行为主体（医疗服务供需双方）的决策作用及影响因素进行分析，建立不合理入院主体决策效应模型；在此基础上，从新农合管理方、医疗服务供需方及政府等方面探索不合理入院的形成机制，并对各成因的贡献进行测量，建立新农合中不合理入院成因的贡献测量模型；并对各成因的可控性进行研究，以便更科学的确定新农合不合理入院的控制水平和有针对性的采取相应措施加强不合理入院的控制。研究中采用田野研究、多水平模型建立新农合不合理入院的决策效应模型；基于不合理住院服务决策效应模型建立影响因素贡献模型；通过专家法、焦点问题访谈法及博弈分析，构建不合理入院的可控性模型。研究结果将有利于丰富和完善医疗保险道德风险的理论，为新农合监管制度、支付方式的改革和补偿政策的再设计提供理论基础，对促进新农合的可持续、健康发展有着较高的理论价值和现实指导意义。

Irrational hospitalization is referred to choice the hospital treatment but not need it. In this project, the behavior agents' (both medical service supply and demand) decision-making role and influence factors were analyzed, and the unreasonable subject admission decision effect model is set up; On this basis, the formation mechanism of irrational hospitalization is explored from the New Rural Cooperative Medical System management, the medical service supply and demand and government, and to measure the contribution of various causes, so to establish irrational hospitalization contribution and measurement model; And study the controllability of the causes so that determining the irrational admission control level scientific and targeted taking corresponding measures to control the irrational hospitalization. In the study, the field research and multiple level model is adopted to establish the irrational admission decision effect model; Based on it to establish contribution factor model; Through expert, the focal point interview method and the gambling analysis, we construct a control model of irrational hospitalization. The results of the study will enrich and perfect the theory of moral hazard of medical treatment insurance, and provide theoretical basis for the payment of the New Rural Cooperative Medical System supervision system, the reform of the mode of payment and the compensation policy' redesigning. That has a higher theoretical value and practical significance in the sustainable and healthy developments of New Rural Cooperative Medical System.