Factors impacting on the activation and approach times of helicopter emergency medical services in four Alpine countries

Background: The outcome of severely injured or ill patients can be time dependent. Short activation and approach times for emergency medical service (EMS) units are widely recognized to be important quality indicators. The use of a helicopter emergency medical service (HEMS) can significantly shorten rescue missions especially in mountainous areas. We aimed to analyze the HEMS characteristics that influence the activation and approach times. Methods: In a multi-centre retrospective study, we analyzed 6121 rescue missions from nineHEMS bases situated in mountainous regions of four European countries. Results: We found large differences in mean activation and approach times among HEMS bases. The shortest mean activation time was 2.9 minutesthe longest 17.0 minutes. The shortest mean approach time was 10.4 minutesthe longest 45.0 minutes. Short times are linked (p < 0.001) to the following conditions: helicopter operator is not state ownedHEMS is integrated in EMSall crew members are at the same locationdoctors come from state or private health institutionsorganization performing HEMS is privately ownedhelicopters are only for HEMSoperation area is around 10.000 km2HEMS activation is by a dispatching centre of regional government who is in charge of making decisionsthere is only one intermediator in the emergency callhelicopter is equipped with hoist or fixed lineHEMS has more than one base with helicopters, and one team per baseclosest neighboring base is 90 km awayHEMS is about 20 years old and has more than 650 missions per yearand modern helicopters are used. Conclusions: An improvement in HEMS activation and approach times is possible. We found 17 factors associated with shorter times