Helicopter emergency medical services accident rates in different international air rescue systems

AIM Each year approximately two to four helicopter emergency medical services (HEMS) crashes occur in Germany. The aim of the present study was to compare crash rates and fatal crash rates in Germany to rates in other countries. MATERIALS AND METHODS A MEDLINE search from 1970 to 2009 was performed using combinations of the keywords "HEMS", "rescue helicopter", "accident", "accident rate", "crash", and "crash rate". The search was supplemented by additional published data. Data were compared on the basis of 10,000 missions and 100,000 helicopter flying hours. These data were allocated to specific time frames for analyis. RESULTS Eleven relevant studies were identified. Five studies (three from Germany, one from the US, one from Australia) analyzing HEMS accidents on the basis of 10,000 missions were identified. Crash rates per 10,000 missions ranged between 0.4 and 3.05 and fatal crash rates between 0.04 and 2.12. In addition, nine studies (six from the US, two from Germany, one from Australia) used 100,000 flying hours as a denominator. Here, crash rates ranged between 1.7 and 13.4 and fatal crash rates between 0.91 and 4.7. CONCLUSIONS Data and accident rates were inhomogeneous and differed significantly. Data analysis was impeded by publication of mean data, use of different time frames, and differences in HEMS systems.