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Reporting Definitions

How to Read the Charts

The charts show the number of events EMS responds to each month broken down by emergency, non-emergency and transfers, as well as response times for the most serious, life-threatening events. For Edmonton and Calgary metro areas, the charts also show times from when an EMS ambulance arrives at an emergency department until that ambulance is available to respond to another call.

Definitions

Dispatch – 9-1-1 calls are routed to an EMS dispatch centre staffed by specially trained individuals, who direct the most appropriate EMS resources to the event.

Event volumes – this is the number of individual events that EMS responds to. They fall into three categories: emergency calls (highest priority), non-emergency calls and patient transfers between health facilities.

Response time – the time from when a call is answered by an emergency call-taker at an EMS dispatch centre until the first EMS unit arrives on scene. AHS reports the response times for life-threatening events, as these events are where time to care is believed to influence patient outcomes.

Median or 50th Percentile – of all the calls responded to, this is the time at which half the responses are faster and half are slower. For example, a median response time of eight minutes means half of all events are responded to within eight minutes and the other half take longer than eight minutes.

90th Percentile – of all the calls responded to, this is the time which 90 per cent are responded within. For example, a 90th percentile response time of 13 minutes means that 90 per cent of all events are responded to within 13 minutes and the other 10 percent take longer than 13 minutes.

Hospital time – the time elapsed from when an EMS ambulance arrives at an emergency department until that ambulance is available to respond to another call. EMS staff must care for their patient until care is formally transferred.