Among Medicare patients with heart attack
in 4 California counties, diversion of ambulance traffic by the nearest emergency department for 12 hours or more was associated with an increased risk of death for up to one year, according to a study in the June 15 issue of JAMA.
This study is being released early online to coincide with its presentation at the AcademyHealth Annual Research Meeting.
Recent reports have described the state of emergency departments (EDs
) in the United States as reaching a breaking point, with the ED system experiencing increased utilization but decreased capacity. These trends have led to problems for patients, such as longer waiting times, overextended staff and disruptions to ambulance services, according to background information in the article. Ambulance diversion, a practice in which EDs are temporarily closed to ambulance traffic due to overcrowding or lack of available resources, might be especially problematic for patients experiencing time-sensitive conditions, such as acute myocardial infarction (AMI; heart attack). There is little empirical evidence to show whether diversion is associated with worse patient outcomes.
Yu-Chu Shen, Ph.D., of the Naval Postgraduate School, Monterey, Calif., and National Bureau of Economic Research, Cambridge, Mass., and Renee Y. Hsia, M.D., M.Sc., of the University of California, San Francisco conducted a study to examine whether temporary ED closure on the day a patient experiences AMI is associated with increased mortality. The study included 13,860 Medicare patients with AMI within 4 California counties (Los Angeles, San Francisco, San Mateo, and Santa Clara) whose admission date was between 2000 and 2005. Data included 100 percent Medicare claims data that covered admissions between 2000 and 2005, linked with date of death until 2006, and daily ambulance diversion logs from the same 4 counties. The researchers indentified 149 EDs as the nearest ED to these patients. Among the outcomes...