BACKGROUND: A retrospective analysis of 7,854 ground ambulance and 1,075 helicopter transports was conducted. METHODS: The 911-hospital arrival intervals for three transport methods were compared: ground, helicopter dispatched simultaneously with ground unit, and helicopter dispatched nonsimultaneously after ground unit response. RESULTS: Compared with ground transports, simultaneously dispatched helicopter transports had significantly shorter 911-hospital arrival intervals at all distances greater than 10 miles from the hospital. Nonsimultaneously dispatched helicopter transport was significantly faster than ground at distances greater than 45 miles, and simultaneous helicopter dispatch was faster than nonsimultaneous at virtually all distances. Ground transport was significantly faster than either air transport modality at distances less than 10 miles from the hospital. CONCLUSION: Ground ambulance transport provided the shortest 911-hospital arrival interval at distances less than 10 miles from the hospital. At distances greater than 10 miles, simultaneously dispatched air transport was faster. Nonsimultaneous dispatched helicopter transport was faster than ground if greater than 45 miles from the hospital.
Diaz et al. (2005) studied this question.