The impact of avalanche transceivers on mortality from avalanche accidents.

Rapid extrication is the most important determinant of survival in avalanche victims. To facilitate rapid localization of avalanche victims by uninjured companions, avalanche transceivers are widely used during off-piste and backcountry activities. Despite their widespread use, the influence of transceivers on survival probability in avalanche accidents is controversial. The aim of this retrospective study was to analyze the influence of transceivers on the mortality of avalanche victims. There were 194 accidents in Austria from 1994 to 2003, involving 278 totally buried victims, which were analyzed. Avalanche transceivers were used by 156 (56%) victims and were associated with a significant reduction in median burial time from 102 to 20 min (p < 0.001), as well as a significant reduction in mortality from 68.0% to 53.8% (p = 0.011). This reduction was due to a decrease in mortality during backcountry activities involving ski tourers in free alpine areas (from 78.9% to 50.4%, p < 0.001). Transceivers did not reduce mortality during off-piste activities beside or near organized ski slopes (67.7% with versus 58.5% without transceiver, not significant). Mortality of persons using a transceiver is significantly higher if burial depth exceeds 1.5 m. Despite a significant reduction, mortality still exceeds 50% even with the use of transceivers. Therefore, in addition to the use of emergency equipment like transceivers, avalanche avoidance measures are critically important. The fairly modest influence of the use of transceivers on survival probability may be due to the highly efficient mountain rescue service in the Austrian Alps. In remote areas the reduction in mortality will probably be far more pronounced.