MONDAY, June 13 (HealthDay News) -- Ambulance diversion lasting 12 or more hours at the emergency department nearest a patient's home on the day of admission is associated with higher mortality in patients with acute myocardial infarction (AMI), according to a study published online June 12 in the Journal of the American Medical Association to coincide with its presentation at the AcademyHealth Annual Research Meeting, held from June 12 to 14 in Seattle.
Yu-Chu Shen, Ph.D., from the Naval Postgraduate School in Monterey, Calif., and Renee Y. Hsia, M.D., from the University of California in San Francisco, investigated whether temporary emergency department closure (measured by ambulance diversion hours) on the day a patient experiences an AMI is associated with increased mortality. Data covering 11,625 AMI admissions between 2000 and 2005 were linked with death date until 2006, and daily ambulance diversion logs. The percentage of AMI deaths within seven hours, 30 days, 90 days, nine months, and one year of admission were measured for no diversion or less than six, six to 12, and 12 hours or more of diversion.
The investigators found that the average daily diversion was 7.9 hours. Mortality rates for patients exposed to no diversion were not statistically significantly different from those exposed to less than 12 hours of diversion. Compared to the no-diversion group, 12 or more hours of diversion correlated with a higher mortality rate at 30 days, 90 days, nine months, and one year.
"Exposure to at least 12 hours of diversion by the nearest emergency department was associated with increased 30-day, 90-day, nine-month, and one-year mortality," the authors write.