ABSTRACT
OBJECTIVES: Helicopter Emergency Medical Services (HEMS) throughout Europe are generally on scene within 10-15 minutes. In Norway, however, with its 13 HEMS bases, only 75% of the population can currently be reached within half an hour. We estimate the number of HEMS bases needed to reach the full Norwegian population within 10-15 minutes, and discuss implications regarding cost effectiveness. METHODS: Using geographic location and population characteristics from Norway's 428 municipalities as input to the Maximal Covering Location Problem-a mathematical location optimization model-we estimate the number of HEMS bases required along with accompanying personnel and healthcare costs. We estimate the minimum number of lives that would have to be saved to achieve a net social benefit of zero. RESULTS: To reach 99% or 100% of the Norwegian population by HEMS within 15 minutes 78 or 104 bases are needed, respectively. The incremental need for personnel going from 20 to 15 minutes for 99/100% of the population is 602/728, with an accompanying incremental cost of 228/276 million EURO per year. A yearly total of 280/339 additional lives would have to be saved to obtain a net social benefit of zero. Then, the HEMS-system as a whole would be cost effective although the least efficient bases still would not be. CONCLUSIONS: Reducing Norwegian HEMS response times to 10-15 minutes requires a drastic increase in the number of HEMS bases needed. Choice of ethical philosophy (utilitarianism or egalitarianism) determines when the expansion might be considered cost effective.
