Melissa McCarthy, ScD¹, Andrew Shore, PhD², Guohua Li, MD DrPH³, Gabor Kelen, MD FACEP⁴, Nelson Tang, MD, FACEP³, Riccardo Colella, DO³, James Scheulen, MBA³, and John New, BA⁵. (1) Department of Emergency Medicine, Johns Hopkins University, Suite 6-111, 1830 East Monument Street, Baltimore, MD 21205, 410-502-8877, mmccarth@jhmi.edu, (2) Department of Health Policy and Management, Johns Hopkins University, 624 North Broadway, Baltimore, MD 21205, (3) Department of Emergency Medicine, Johns Hopkins University School of Medicine, 1830 East Monument Street, Baltimore, MD 21205, (4) Johns Hopkins Department of Emergency Medicine, Office of Critical Event Preparedness and Response, 1830 East Monument Street, Suite 6100, Baltimore, MD 21287, (5) Maryland Institute for Emergency Medical Services Systems, 653 West Pratt Street, Baltimore, MD 21201

Purpose. To describe how frequently ambulance providers reroute patients because hospitals are on diversion and to determine the factors associated with reroute.

Methods. Hospital diversion and ambulance run data for region IIIA of Maryland for 2000 were obtained and merged. Of the 128,149 ambulance transports that occurred, 18,128 (14%) were eligible for diversion based on the patient’s priority level and the diversion status of the closest hospital at the time of transport. The influence of patient, clinical and hospital characteristics on the likelihood of reroute was examined using multivariate logistic regression.

Results. In 2000, the 15 region IIIA hospitals were on hospital diversion 25% of the time (range 8% to 53%). Of the 18,128 patients transported during diversion periods, 19% were rerouted and 81% were brought to a hospital requesting diversion. The more hospitals simultaneously on diversion, the less likely a patient was rerouted (OR=0.91, 95% CI 0.90, 0.93). Furthermore, the more frequently a hospital utilized diversion, the less likely patients were rerouted (OR=0.94, 95% CI 0.94, 0.94). Patient factors that significantly influenced the likelihood of being rerouted included older age, non white race and priority level 3.

Conclusions. Prehospital providers often have no choice but to bring patients to a hospital on diversion because neighboring hospitals are also on diversion. Ambulance diversion protocols are of limited effectiveness. Future research is needed to determine if adverse patient outcomes occur more frequently during periods when hospitals are operating beyond their capacities.

Learning Objectives: Participants in this session will be able to

(
• Define hospital diversion policies and their impact on prehospital transports (
• List the factors that influence whether prehospital providers reroute or bring patients to hospitals on diversion.

Keywords: Emergency Department/Room, Access and Services

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.