Liang Li-Lin
China Center for Health Development Studies, Peking University, Beijing, China.
Health Econ. 2015 Apr;24(4):454-69. doi: 10.1002/hec.3033. Epub 2014 Feb 12.
This study investigates whether the diagnosis-related group (DRG)-based payment method motivates hospitals to adjust output mix in order to maximise profits. The hypothesis is that when there is an increase in profitability of a DRG, hospitals will increase the proportion of that DRG (own-price effects) and decrease those of other DRGs (cross-price effects), except in cases where there are scope economies in producing two different DRGs. This conjecture is tested in the context of the case payment scheme (CPS) under Taiwan's National Health Insurance programme over the period of July 1999 to December 2004. To tackle endogeneity of DRG profitability and treatment policy, a fixed-effects three-stage least squares method is applied. The results support the hypothesised own-price and cross-price effects, showing that DRGs which share similar resources appear to be complements rather substitutes. For-profit hospitals do not appear to be more responsive to DRG profitability, possibly because of their institutional characteristics and bonds with local communities. The key conclusion is that DRG-based payments will encourage a type of 'product-range' specialisation, which may improve hospital efficiency in the long run. However, further research is needed on how changes in output mix impact patient access and pay-outs of health insurance.
本研究调查基于诊断相关分组（DRG）的支付方式是否促使医院调整产出组合以实现利润最大化。假设是，当某个DRG的盈利能力提高时，医院会增加该DRG的比例（自身价格效应），并降低其他DRG的比例（交叉价格效应），除非在生产两种不同DRG存在范围经济的情况下。这一推测在1999年7月至2004年12月期间台湾全民健康保险计划的病例支付方案（CPS）背景下进行了检验。为解决DRG盈利能力和治疗政策的内生性问题，采用了固定效应三阶段最小二乘法。结果支持了假设的自身价格和交叉价格效应，表明共享相似资源的DRG似乎是互补品而非替代品。营利性医院似乎对DRG盈利能力的反应并不更强烈，这可能是由于其机构特征以及与当地社区的联系。关键结论是，基于DRG的支付将鼓励一种“产品范围”专业化，从长远来看可能会提高医院效率。然而，关于产出组合的变化如何影响患者获得医疗服务的机会和医疗保险赔付，还需要进一步研究。
