Ambulance Diversion
Ambulance diversion is when a hospital temporarily closes its Emergency Department (ED) to ambulances, and ambulances are then diverted to other hospitals. Measuring ambulance diversion is important because it represents when an ED is overcapacity. While diversion does allow an ED to slow down the in-coming flow of ambulance patients, it may add extra travel time for 911 ambulances and patients may not be able to go to their preferred hospital. Key providers in the San Francisco emergency medical system are working together to monitor the impact of diversion and identify strategies to reduce it and increase patient care access.
San Francisco EMSA Diversion Policy
Diversion Policy 5020 establishes guidelines for when hospital emergency departments may divert 911 ambulance patients. A hospital may declare “Ambulance Diversion” only when there is an issue that may lead to a decreased level of care for the next ambulance patient, such as having an overload of patients requiring immediate attention.
When a receiving hospital is on “Diversion,” no patient shall be transported to that hospital by ambulance except for critical circumstances such as a patient in imminent or full respiratory or cardiac arrest, or when a patient has a special medical need such as significant burns or trauma. Diversion also does not affect patients that are transferred from a hospital clinic to the Emergency Department.
Select a hospital below to view that hospital's monthly percentage of hours on diversion from September 2011 to present. Adjust the date range as desired.
When a receiving hospital is on “Diversion,” no patient shall be transported to that hospital by ambulance except for critical circumstances such as a patient in imminent or full respiratory or cardiac arrest, or when a patient has a special medical need such as significant burns or trauma. Diversion also does not affect patients that are transferred from a hospital clinic to the Emergency Department.
Select a hospital below to view that hospital's monthly percentage of hours on diversion from September 2011 to present. Adjust the date range as desired.
Diversion Suspension
Diversion is “suspended” (temporarily halted) when four or more full receiving hospitals are on “Diversion” (see Policy 5020). Diversion suspension requires all receiving hospitals to accept all EMS transported patients. The intent is to keep a critical number of hospitals open to the 911 ambulance system. Since Zuckerberg San Francisco General is the city’s only Trauma Center, it uses “Trauma Override” during diversion suspension to maintain its capacity for trauma patients.
The chart below shows the percentage of hours that diversion was suspended in each month and the number of transports in each month from December 2014 - present. Hover over a point to see the number and percentage of hours that diversion was suspended (or the number of transports) in that month.
The chart below shows the percentage of hours that diversion was suspended in each month and the number of transports in each month from December 2014 - present. Hover over a point to see the number and percentage of hours that diversion was suspended (or the number of transports) in that month.
Emergency department (ED) volume is another informative comparison point for diversion suspension. The Office of Statewide Health Planning and Development (OSHPD) releases statewide data such ED Encounters by Facility, though the data is not available monthly. Find OSHPD data here.
