Disease staging as a measure of disease severity.

Disease staging, first developed in 1970, has been used to assess the levels of biological severity, defined as the risk of organ failure or death, of specific medical diseases. Because few studies to date have evaluated disease staging in Japan, a small pilot study was designed to determine whether disease staging is available and useful in actual medical practice in Japan. The relationships between disease staging and length of stay, medical costs and age were retrospectively evaluated in patients admitted to Japan Association for Development of Community Medicine - Tokyo Bay Urayasu Ichikawa Medical Center for appendicitis, type 2 diabetes mellitus, and cerebrovascular diseases from April 2012 to March 2013. Patients were easily staged based on information at the time of hospital discharge. Disease stages were found to be affected significantly by length of hospital stay and medical costs. Age also affected disease stages in patients with appendicitis. These findings indicate that disease staging was available in Japan and was affected by hospital resources, including length of hospital stay and medical costs.