Interfacility Transport of Emergency Department Patients by Helicopter Air Ambulance: A Simulation Study of Utilization.

OBJECTIVE: Interfacility transports by helicopter air ambulance (IFT-HAAs) are requested for critically ill and injured patients. Requests for patient transport may originate from several settings within the referring facility: the emergency department (ED), procedural areas (such as a cardiac catheterization laboratory), or inpatient units such as an intensive care unit. Existing literature has not clarified the contributions of the ED compared with other facility settings. METHODS: In this retrospective modeling study, we used data from the Federal Aviation Administration, National Hospital Ambulatory Medical Care Survey, and flight request data from a multicenter convenience sample of 3 nonprofit, hospital-based helicopter air ambulance operators between 2016 and 2018. We used a deterministic model to estimate the proportions of all IFT-HAAs originating from the ED and the proportion of ED patients intended for disposition by IFT-HAA. RESULTS: Compared with all other hospital care settings, the ED is the source of more than 75% of all IFT-HAAs in this sample of 3 flight programs. Nationally, IFT-HAA is estimated as the intended disposition for approximately 0.2% of all ED patients; this result seems stable over the 3 years included in this study. CONCLUSION: The intended disposition for 0.2% of ED visits is estimated to be IFT-HAA. Given that ED-dispositioned patients represent more than 75% of all IFT-HAAs in this sample of 3 flight programs, efforts to promote appropriate utilization of IFT-HAA should prioritize engagement with emergency physicians.