Response time (RT) has been liberally used as a process indicator to assess emergency medical services (EMS) performance around the world. It is objective, quantifiable, and easily understood by the public and policymakers alike. However, its correlation to better patient outcome is yet to be established. The evidence supporting the value of using RT is mostly lacking and the little existing evidence is conflicting. There is a concern that the RT notion is dominating the professional culture of ambulance providers. Quality of patient care is becoming a secondary target to RT. Solutions to shorten RT of ambulance services have prohibitive costs and risk the safety of patients, attending crew and the public. It is time to consider patient outcome as the main standard for performance of EMS in order to meet the public expectation of accountability and openness.
Keywords: EMS; ambulance; outcome; performance; response time.