The risk factors for mortality of community-acquired pneumonia in Japan.

Community-acquired pneumonia remains one of the most important diseases associated with mortality. The aim of this study was to identify the risk factors for mortality in patients with community-acquired pneumonia in Japan. This prospective study was carried out at the Social Insurance Tagawa Hospital, Fukuoka, Japan. All patients were managed according to the 1993 American Thoracic Society guidelines for community-acquired pneumonia, after an evaluation of the risk class by the pneumonia Patient Outcome Research Team (PORT) study. A comparison of several factors, including demographic findings, clinical signs, underlying diseases, results of medical examinations, severity of diseases, and causative pathogens in both survival and fatal groups, was carried out from 227 episodes of community-acquired pneumonia in 208 hospitalized patients (128 men, mean age 67.7 years). The presence of a risk of aspiration, low systolic blood pressure, low PaO(2)/FIO(2) ratio, a high pneumonia score, and the presence of severe congestive heart failure were found to be independent risk factors for mortality from community-acquired pneumonia. The mortality in risk classes IV and V was 17.5% and 54.2%, respectively, and there was a significant correlation between risk classes. The risk factors we identify here are generally similar to those given in previous reports in Western countries. According to the prediction rule of the pneumonia PORT study, the risk classes were strongly associated with the mortality, and would be suitable and helpful for the management of patients with community-acquired pneumonia in Japan.