共同诊疗实践：联邦医疗保险对私人医疗服务的溢出效应

中文摘要

美国提高医疗服务生产率的进展缓慢，这可能源于支付体系在不同保险机构之间的碎片化。每家保险机构为改善医疗服务所作的努力都可能影响医生为其他保险机构参保人诊疗的方式，从而产生未被计价的外部性。我们研究了联邦医疗保险为遏制抗精神病药物过度使用而实施的一项随机信函干预。信函并未提及私人保险，却使医生对这些私人保险患者的处方量减少了12%，与联邦医疗保险患者中17%的降幅相近。我们无法拒绝一比一溢出效应的假设，这表明医生在不同保险机构的患者间采用相似的医疗实践风格。我们的研究结果证实，保险机构能够对远超其直接管辖范围的医疗服务产生影响。（JEL D24、G22、I11、I13、I18）

Abstract

Efforts to raise US health-care productivity have proceeded slowly, potentially due to the fragmentation of payment across insurers. Each insurer’s efforts to improve care could influence how doctors practice for other insurers, leading to unvalued externalities. We study a randomized letter intervention by Medicare to curtail overuse of antipsychotics. The letters did not mention private insurance but reduced prescribing to these patients by 12 percent, much like the 17 percent effect in Medicare. We cannot reject onefor-one spillovers, suggesting that physicians use similar medical practice styles across insurers. Our findings establish that insurers can affect health care well outside their direct purview. (JEL D24, G22, I11, I13, I18)