Fig. 1

Flow chart showing all primary HEMS dispatches, with excluded and completed missions. Primary missions were defined as responses to patients outside hospitals. ^aDeclined dispatches or aborted missions were due to medical indication no longer being present, weather, concurrent missions, unable to perform a flight, or other reasons; 109 of the declined and 33 of the aborted missions (total 0.8% of the dispatches) were transferred to another HEMS in the area. Therefore, these incidents are reported as two separate dispatches. ^bThe characteristics of the 41 entrapped patients are presented in Additional File 1. ^cHEMS base very close to the incident, completed without using a vehicle