n Western countries, the mean length of hospital stay after acute myocardial infarction (AMI) has declined dramatically during the past 3 decades. In the 1970s, the length of hospital stay after AMI was generally 2-3 weeks, 1,2 although several randomized studies subsequently suggested the feasibility, safety, and cost effectiveness of discharging patients as early as 3-5 days after AMI. [3][4][5] Since then, the hospital stay after AMI has reduced to the current length of approximately 1 week in Western countries. [6][7][8][9] In contrast, the length of stay after AMI remains at approximately 4 weeks in Japan, [10][11][12][13][14] and epidemiological data concerning the length of hospital stay after AMI, its predictors and trends based on a large-scale sample are still limited. The Osaka Acute Coronary Insufficiency Study (OACIS), a large registry of patients with AMI, was established in 1998 to assess clinical variables, therapeutic procedures and clinical events, and can provide important data about recent trends in the pattern of care. The purpose of the present study was to examine the length of hospital stay after AMI as well as to identify the predictors and trends in hospital stay after AMI in Japan.
Circulation Journal Vol.68, September 2004
Methods
Purpose of the RegistryA detailed description of the OACIS has been published elsewhere. 15,16 The OACIS was a prospective, multicenter observational study involving 25 collaborating hospitals in the Osaka region of Japan. The registry was designed to collect uniform, prospective data on patients with AMI that could be used to assess clinical variables, therapeutic procedures and clinical events, and to collect DNA samples from the patients that could be used to investigate whether common genetic variations are involved in the pathogenesis of AMI. The study protocol was approved by each hospital's ethics committee.
DefinitionsDiagnosis of AMI required the presence of 2 of the following 3 criteria: (1) a clinical history of central chest pressure, pain, or tightness lasting 30 min or more, (2) typical electrocardiographic changes (ie, ST segment elevation greater than 0.1 mV in at least 1 standard or 2 precordial leads, ST segment depression greater than 0.1 mV in at least 2 leads, abnormal Q waves, or T wave inversion in at least 2 leads), and (3) an increase of serum creatine kinase to 2-fold the upper limit of normal. All patients presenting within 1 week after the onset of AMI were registered prospectively, as soon as a diagnosis of AMI was made.
Data CollectionResearch cardiologists and specialized research nurses recorded the data on the demographic variables, medical history, therapeutic procedures, and clinical events during the patient's hospital stay. Information was obtained from Background In Western countries, the length of hospital stay after acute myocardial infarction (AMI) has decreased dramatically during the past 3 decades and is now approximately 1 week. However, epidemiological data concerning the length of hospital stay, its predictors a...