Response Time and Its Significance in Medical Emergencies

HT HE Emergency Medical Systems Service Act (EMSS Act) of 1973 was passed by Congress to promote systematic planning and evaluation of regional emergency systems. The Act represented an attempt to coordinate a number of components in prehospital emergency cases, such as transportation, personnel, and facilities. One of the provisions of the EMSS Act is that 95 percent of all ambulance response times must be within twenty minutes in rural areas and within ten minutes in urban areas. Compliance with response-time criteria is largely a geographical problem. In terms of any given population distribution, how may emergency units be most efficiently allocated? This allocation problem is such that its solution may be solved by location-allocation models and their various derivatives. Thus geographical attention to emergency medical systems has concentrated largely on the solution of the local problem.' The "objective function" has been structured in several ways: to minimize response time subject to a cost constraint; to minimize cost subject to a response time constraint; to ensure that a certain percentage of emergency calls are answered within a specified time period. Cost has been an increasingly important issue because it is theoretically possible, but obviously impractical, to locate one ambulance on every city block and hence to ensure a minimal response time. The two major variables that may be manipulated are the number of emergency vehicles and their locations.