Background: Since cardiovascular disease accounts for one-quarter of deaths in the Japanese population, we developed a nationwide database using the administrative case-mix Diagnostic Procedure Combination (DPC) system (ie, theJapaneseRegistryOfAll cardiac and vascularDiseases (JROAD)-DPC) to reveal the current status of cardiovascular medicine in Japan.Methods and Results:The JROAD-DPC database included 704,593 health records' data of 2012 from 610 certificated hospitals of the Japanese Circulation Society. The 35,824 patients with acute myocardial infarction (AMI) and 108,665 patients with heart failure (HF) were admitted to hospitals. Increased hospital case volume was associated with reduced in-hospital mortality rates for both AMI and HF (P for trend <0.001). Although there was little variation among AMI patients in terms of aspirin use at discharge (median prescription rate, 83.0%; interquartile range [IQR], 76.9-88.0%), there were wide variations in the proportions of patients prescribed β-blockers (BB) and angiotensin-converting enzyme inhibitors (ACEI)/angiotensin-receptor blockers (ARB) at discharge (BB, 41.4%, IQR 27.6-55.7%; ACEI/ARB, 52.0%, IQR 40.3-62.3%). In patients with HF, there were between-hospital variations in medications at discharge (BB, 38.1%, IQR, 27.8-47.6%; ACEI/ARB, 41.0%, IQR 31.7-49.1%).
Conclusions: A nationwide administrative database of patients with cardiovascular diseases (JROAD-DPC) provided useful information that will contribute to improved quality of medical care, especially in the aging society of Japan, where HF has become an important health problem. (Circ J 2016; 80: 2327-2335).