How dangerous is BASE jumping? An analysis of adverse events in 20,850 jumps from the Kjerag Massif, Norway

Background: Extreme sports, including BASE (building, antenna, span, earth) jumping, are rapidly increasing in popularity. Associated with risk for injuries and deaths, this activity may pose a burden on the emergency system. Hitherto, no reports exist on accidents and deaths associated with BASE jumping. Methods: We reviewed records of 20,850 BASE jumps from 1995 to 2005 at the Kjerag massif in Norway. Frequency of deaths, accidents, and involvement of helicopter and climbers in rescue are analyzed. Fatalities were scored for injury severity scores (Abbreviated Injury Scale score, Injury Severity Score, New Injury Severity Score) on autopsy. Results: During an 11-year period, a total of 20,850 jumps (median, 1,959; range, 400-3,000) resulted in 9 fatal (0.04% of all jumps; I in every 2,317 jumps) and 82 nonfatal accidents (0.4% of all jumps; 1 in every 254 jumps). Accidents increased with the number of jumps (r = 0.66; p = 0.007), but fatalities did not increase, nor did activation of helicopter or climbers in rescue (p > 0.05). Helicopter activation (in one-third of accidents) in rescue correlated with number of accidents (r = 0.76, p = 0.007), but not climbers. Postmortem examination (n = 7) of fatalities revealed multiple, severe injuries (Abbreviated Injury Scale score >= 3) sustained in several body regions (median, Injury Severity Score 75; range, 23-75). Most nonfatal accidents were related to ankle sprains/fracture, minor head concussion, or a bruised knee. Conclusion: BASE jumping appears to hold a five- to eightfold increased risk of injury or death compared with that of skydiving. The number of accidents and helicopter activation increases with the annual number of jumps. Further analysis into the injury severity spectrum and associated hospital burden is required.