Where emergency calls are prioritised, Category A emergencies are those which are immediately life threatening and Category B emergencies are those which are not life threatening. For both Category A and Category B calls an emergency response can initially be a rapid response vehicle crewed by a paramedic equipped to provide treatment at the scene of the incident, or an approved first responder despatched by, and accountable to, the ambulance service. An emergency ambulance, ie a fully equipped emergency vehicle able to transport the patient, is required to attend the incident unless the control room decides that an ambulance is not required. 3.3 An Urgent transport request is defined as a request when a definite time limit is imposed such that the vehicle and crew must be despatched quickly, although not necessarily immediately, to collect a patient, perhaps seriously ill, on the advice of a doctor for admission to hospital. 3.5 Response Time starts when details of the telephone number of the caller, the exact location of the incident and the nature of the chief complaint have been ascertained.
Response time ends when the emergency response vehicle arrives at the scene of the incident.
Where calls are prioritised, the arrival of a rapid response vehicle crewed by a paramedic equipped to provide treatment at the scene, or an approved first responder despatched by and accountable to the ambulance service, counts in calculating response against the 8-minute standard for both Category A and Category B emergency calls. For those ambulance services which have not introduced prioritisation the prior arrival of any other vehicle, such as a rapid response vehicle does not count in calculating response time. Also, some services had been recording response time to the nearest minute rather than, as is now required, to the nearest second. 3.7 Urban services are those where the population density of the area covered was more than 2.5 persons per acre in 1991. 3.8 Rural services are those where the population density of the area covered was less than 2.5 persons per acre in 1991.