Internet-accessible emergency department workload information reduces ambulance diversion.

Objective: To determine the effect of pre-emptive ambulance distribution based on the implementation of a real-time, Internet-accessible emergency department (ED) workload schematic and prehospital Australasian Triage Scale (ATS) allocations on ambulance diversion in Western Australia.

Methods: Comparison of July-December 2002 and July-December 2003 metropolitan Perth ED cubicle occupancy, ambulance diversion, ambulance distribution, and ambulance unloading delays at four inner and four outer metropolitan EDs.

Results: Ambulance diversion fell from 1,788 hours in 2002 to 1,138 hours in 2003 (p < 0.