San Mateo County
Ambulance Patient Offload Times


Timely transfer of patient care from EMS to hospital staff is widely known to improve the availability of ambulances and patient safety. As such, hospitals play a crucial role in ensuring that 9-1-1 ambulances are available for the next request for emergency service. 

Ambulance patient offload time (APOT) is the standard metric used  to monitor this performance measure. In its simplest description, APOT is a calculation of the difference of time from the ambulance arriving at the hospital to the time patient care is transferred to hospital staff. Transfer of care is considered complete when a patient is  transferred from the EMS gurney and a verbal report has been provided to receiving hospital staff. Activities performed after transfer of care is completed (e.g., ambulance clean up and restock) are not considered in the APOT calculation.

APOT is calculated for all hospitals who receive 9-1-1 patients from San Mateo County. The County has set an expectation that 9 out of 10 patients are transferred to the care of hospital staff within 30 minutes of ambulance arrival. Although uncommon, patient offload delays in excess of 30 minutes do occur. Transfers in excess of 60 minutes are classified as "transfer delays" and are reviewed on a case-by-case basis.

Information presented in this report is based on patient data provided by San Mateo County 9-1-1 ambulance providers.

APOT Performance: Previous 7 Days

Previous 7 days data is updated daily Monday through Friday.

Previous 21 days data is updated daily Monday through Friday.

9-1-1 Transport Volume: Previous Month

APOT Performance: Previous Month

APOT is a critical element in the performance of the San Mateo County EMS system. 

Delayed APOT can directly impact the availability of 9-1-1 ambulances to those in need. Thus, the expectation is that each patient transported by a 9-1-1 ambulance to a hospital be transferred to the care of receiving hospital staff within 30 minutes of arrival at the hospital, 90% of the time.

The San Mateo County EMS Agency has regulatory jurisdiction of 9-1-1 receiving hospitals within San Mateo County. However, we work in close partnership with neighboring EMS agencies to ensure that similar standards exist for patients transported to out-of-county hospitals.

Transfer delays are defined as the delay of transfer of care between EMS and receiving hospital staff. Transfer delays of 60 minutes or more are significant events that warrant review. These are serious and largely preventable patient safety incidents that impact not only the continuum of patient care but also the availability of EMS resources to respond to emergency requests for service within the 9-1-1 system.

Transfer Delays

APOT Performance: Historical Comparison

Monthly APOT performance provides an insight into the performance of the larger EMS system. In order to better understand APOT by facility, we trend performance month-over-month. This provides a more accurate portrayal of long-term performance while highlighting anomalies that may occur.

The County works with ambulance providers and hospital leadership to ensure prompt patient transfer in the hospital. Prompt transfer enables timely definitive care and the return of emergency ambulances into the system for the next 9-1-1 response. 

The San Mateo County Emergency Medical Services Agency, in compliance with Health and Safety Code 1797.120, calculates and reports ambulance patient offload times using standardized criteria and methodology monthly.