Predictors of length of hospital stay after acute myocardial infarction in Japan

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 and trends based on a large-scale sample are still limited in Japan. Methods and Results The study group comprised 4,113 surviving AMI patients who were enrolled in the Osaka Acute Coronary Insufficiency Study from April 1998 to March 2003. The mean length of hospital stay was 31.2 days. Clinical factors (patient characteristics, severity of infarction, therapy, and in-hospital complications) only explained 26% of the variation in hospital stay. The mean hospital stay was significantly longer in 1998 than in 2002. In 2002, occupational status and admission to a high-volume hospital were independent predictors of a shorter hospital stay, but this association was not observed in 1998. Conclusions The hospital stay is still extremely long in Japan and clinical factors do not provide an explanation. The findings of the present study suggest that the hospital stay could be reduced in some patients with AMI, but randomized studies are needed to examine the feasibility of early discharge.