Hospital Volume and Quality of Care

描述：在治疗大量有类似情况的患者的医院里，医生将获得最有效的治疗经验。人们会认为，这种专业知识应该反映在更好的健康结果中(熟能生巧的假说)。然而，使用观察数据，由于患者更喜欢被认为是更好的医院，从而产生了选择偏差，从而在容量和结果之间产生了虚假的相关性(选择性转诊假说)。全面了解医院容量和健康结果之间的关系是一项高度优先的政策。虽然大量的医疗干预已经很好地证明了医院容量和护理质量之间的正向关系，但很少有研究试图控制由于选择性转诊而造成的选择性偏差。这项拟议的研究将利用现有的两个数据库，以更好地了解医院容量和健康结果之间关系的原因。该项目有以下两个具体目标：1)获得医院容量对健康结果影响的公正估计。2)分析采用技术以来的时间和积累的经验对护理质量的影响。 我们的数据将来自合作心血管项目(CCP)(1994至1995年间因急性心肌梗死(AMI)入院的医疗保险患者的样本)，我们将使用全国范围的非患者样本(NIS)来衡量医院容量和采用特定技术的年份。CCP数据在研究医院数量和健康结果之间的关系方面有几个优势：1)它是一个具有全国代表性的大样本，2)它包含关于医院后死亡率和再入院的信息，3)它包含关于入院时病情严重程度和所执行程序的非常详细的信息，4)它包含患者的邮政编码，这将为我们提供比以前研究更好的工具。

DESCRIPTION: Physicians in hospitals that treat a large number of patients with a similar condition will gain experience about the most effective treatments. One would assume this expertise should be reflected in better health outcomes (practice-makes-perfect hypothesis). However, using observational data, a selection bias arises since patients prefer the perceived "better" hospital, creating a spurious correlation between volume and outcomes (selective-referrals hypothesis). Gaining a comprehensive understanding of the relationship between hospital volume and health outcomes commands a high policy priority. Although the positive relationship between hospital volume and quality of care has been well documented for a large number of medical interventions, few studies have tried to control for the selectivity bias due to selective referrals. The proposed research will take advantage of two existing data bases to better understand the causes of the relationship between hospital volume and health outcomes. This project has the following two specific aims: 1) Obtain unbiased estimates of the effect of hospital volume on health outcomes. 2) Analyze the effects of time since technology adoption and accumulated experience on quality of care. Our data will come from the Cooperative Cardiovascular Project (CCP) (a sample of Medicare patients who were admitted for an acute myocardial infarction (AMI) between 1994 and 1995) and we will use the Nationwide Impatient Sample (NIS) to measure hospital volume and the year when a particular technology was adopted. The CCP data has several advantages to study the relation between hospital volume and health outcomes: 1) It is a large and nationally representative sample, 2) It contains information on post-hospital mortality and readmissions, 3) it contains very detailed information on the severity of illness at admission and the procedures performed, 4) it contains the patient's zip code which will provide us with better instruments than previous studies.