Røislien Jo, van den Berg Pieter L, Lindner Thomas, Zakariassen Erik, Aardal Karen, van Essen J Theresia
Department of Health Studies, University of Stavanger, Stavanger, Norway.
Department of Research, Norwegian Air Ambulance Foundation, Drøbak, Norway.
Inj Prev. 2017 Feb;23(1):10-15. doi: 10.1136/injuryprev-2016-041973. Epub 2016 Jun 20.
Helicopter emergency medical services are an important part of many healthcare systems. Norway has a nationwide physician staffed air ambulance service with 12 bases servicing a country with large geographical variations in population density. The aim of the study was to estimate optimal air ambulance base locations.
We used high resolution population data for Norway from 2015, dividing Norway into >300 000 1 km×1 km cells. Inhabited cells had a median (5-95 percentile) of 13 (1-391) inhabitants. Optimal helicopter base locations were estimated using the maximal covering location problem facility location optimisation model, exploring the number of bases needed to cover various fractions of the population for time thresholds 30 and 45 min, both in green field scenarios and conditioning on the current base structure. We reanalysed on municipality level data to explore the potential information loss using coarser population data.
For a 45 min threshold, 90% of the population could be covered using four bases, and 100% using nine bases. Given the existing bases, the calculations imply the need for two more bases to achieve full coverage. Decreasing the threshold to 30 min approximately doubles the number of bases needed. Results using municipality level data were remarkably similar to those using fine grid information.
The whole population could be reached in 45 min or less using nine optimally placed bases. The current base structure could be improved by moving or adding one or two select bases. Municipality level data appears sufficient for proper analysis.
直升机紧急医疗服务是许多医疗系统的重要组成部分。挪威拥有一项由医生提供人员配备的全国性空中救护服务，设有12个基地，为一个人口密度地理差异较大的国家提供服务。本研究的目的是估计空中救护基地的最佳位置。
我们使用了2015年挪威的高分辨率人口数据，将挪威划分为超过30万个1千米×1千米的单元格。有人居住的单元格的中位数（第5至95百分位数）为13（1至391）人。使用最大覆盖选址问题设施选址优化模型估计最佳直升机基地位置，探索在30分钟和45分钟时间阈值下覆盖不同比例人口所需的基地数量，包括在未开发场景以及以当前基地结构为条件的情况下。我们对市政层面的数据进行重新分析，以探索使用更粗略的人口数据时潜在的信息损失。
对于45分钟的阈值，使用4个基地可以覆盖90%的人口，使用9个基地可以覆盖100%的人口。考虑到现有的基地，计算结果表明需要再增加2个基地才能实现全面覆盖。将阈值降低到30分钟，所需基地数量大约会增加一倍。使用市政层面数据的结果与使用精细网格信息的结果非常相似。
通过优化设置9个基地，可以在45分钟或更短时间内覆盖全体人口。通过移动或增加一两个选定的基地，可以改善当前的基地结构。市政层面的数据似乎足以进行适当的分析。
