Community trial to decrease ambulance diversion hours: the San Diego county patient destination trial

Emergency department (ED) ambulance diversion is a major issue in many communities. When patients do not reach requested facilities, challenges in care are compounded by lack of available medical records and delays in transferring admitted patients back to the originally requested facility. We seek to evaluate a community intervention to reduce ambulance diversion.

This was a community intervention in a county of 2.8 million individuals. Ambulance diversion guidelines were revised for all ambulance agencies and EDs. Participation by EDs was voluntary, and main outcome measures, which included ambulance transports, ambulance diversions, and bypass hours, were compared for the pretrial, trial, and posttrial periods.

A total of 235,766 patients were transported to an ED by advanced life support ambulance during the 2-year study period. There was a significant decrease in the number of patients who did not reach the requested facility because of ambulance diversion for the trial period (n=322) and posttrial period (n=449) compared with the pretrial period (n=1,320; -998 diverted patients per month [95% confidence interval (CI) -1,162 to -833 patients] and -871 diverted patients per month [95% CI -963 to -780 patients], respectively). There was also a significant decrease in average monthly hours on diversion for the trial period (n=1,079) and posttrial period (n=1,774) compared with the pretrial period (n=4,007; -2,928 hours on bypass [95% CI -3,936 to -1,919 hours on bypass] and -2,232 hours on bypass [95% CI -3,620 to -2,235 hours on bypass], respectively).

A voluntary community-wide approach to reducing hospital ED diversion and getting more ambulance patients to requested facilities was effective.