A Study of Quality of Care Measurements: Treatment Effect Estimates of Percutaneous Transluminal Coronary Angioplasty (PTCA) on Acute Myocardial Infarction (AMI) Patients (ESRI Users' Manual for Micro-Level AMI Database 2003)(in Japanese)

Like other developed countries, Japan currently has been experiencing a rapid increase in medical care costs. It is one of imperative interests for the government to find an effective way of balancing the quality and costs of medical care. As of 2003, the Economic and Social Research Institute (ESRI) of Cabinet Office has started a research project collecting a micro-level data on the national health separately by major disease such as heart attacks, strokes, and cancers. This project aims to look into the public health system to implement results based on micro-level empirical studies on the relation between the quality and costs of medical care. On the first stage of the project, we create the database on patients with acute myocardial infarction (AMI). In particular, we focus on effects of a major high-tech treatment - percutaneous transluminal coronary angioplasty (PTCA) on patient outcomes and medical costs, which have been examined by a number of previous studies in the United States. This discussion paper serves as user's manual to provide several findings from a basic statistics of the micro-level database on AMI. This paper informs users several key issues including background information on data collection, data structure, and definitions of key variables. The ESRI plans to make the electronic database available to the public on the website in the near future. This paper consists of two parts. Part 1 describes the public health plans conducted by the CMS (Center for Medicare and Medicaid Services) and a number of previous studies in the United States, in order to emphasize the importance of implementing results of empirical tests into the actual public policy. Part 2 is the user's manual and discusses a major statistical issue when using observational data to measure the quality of care-heterogeneity. We compare basic statistics of data on AMI patients in Japan, the United States and China. Due to serious heterogeneity problem in observational data, we have to control for various risks in order for measuring treatment effects on patient outcomes and costs correctly. Besides, the technological innovations in medical care are so rapid and complex that it is difficult to evaluate treatment effects. Therefore, as future agenda, it matters that nation-wide micro-level data including detailed chart-based information would be available not only for AMI but also other diseases which contribute to increase medical costs in Japan enormously.