Spatial analysis of mortality rate of pedestrian accidents in Iran during 2012–2013

<b>Objectives:</b> Considering the high mortality rate of pedestrians in traffic accidents in Iran, the present study aimed to determine the high-risk and low-risk areas of accidents resulting in pedestrian deaths and the spatial analysis of their mortality rates. <b>Methods:</b> This cross-sectional study included 4,371 deceased pedestrians reported by the Legal Medicine Organization in Iran from March 2012 to March 2013. For spatial analysis, the collected data were entered into ArcGIS software version 10.2 and a spatial map of the mortality rate was drawn according to the distribution of data in the provinces. Using this software, high-risk and low-risk areas were identified by calculating the spatial autocorrelation of the data. The Moran’s index of road accident patterns was surveyed and high-risk and low-risk points were identified using the local Getis index. <b>Results:</b> The age-standardized incidence rate was 6.8 per 100,000. After analyzing the data using ArcGIS software, the local Moran’s index showed a cluster pattern with a high mortality rate in 3 provinces of Mazandaran, Gilan, and Qazvin. In identifying high-risk and low-risk points, the local Getis index showed 3 hot spots with a confidence interval of 99% in Qom, Qazvin, and Mazandaran and 5 hot spots with a 95% confidence interval in Markazi, Tehran, Zanjan, Gilan, and Golestan provinces. <b>Conclusions:</b> According to the cluster pattern of accidents in the 3 provinces and the presence of hot spots in 9 provinces, it is necessary to identify factors that increase the risk of death in the study provinces in order to reduce the mortality rate among pedestrians due to traffic accidents. Therefore, to reduce the pedestrian mortality rate, especially in high-risk provinces, some studies need to be conducted to determine the risk factors in pedestrian mortality.

**研究目的**：鉴于伊朗行人在道路交通事故中死亡率居高不下，本研究旨在明确引发行人死亡的交通事故的高风险与低风险区域，并对其死亡率开展空间分析。
**研究方法**：本项横断面研究纳入了2012年3月至2013年3月期间伊朗法医组织（Legal Medicine Organization）上报的4371名已故行人数据。为开展空间分析，研究人员将收集到的数据导入ArcGIS 10.2软件，并依据各省的数据分布绘制了死亡率空间分布图。借助该软件，通过计算数据的空间自相关（spatial autocorrelation）特性识别高风险与低风险区域；对道路交通事故分布模式的莫兰指数（Moran’s index）进行测算，并利用局部盖氏指数（local Getis index）识别高风险与低风险点位。
**研究结果**：年龄标化发病率为6.8/10万。经ArcGIS软件数据分析后，局部莫兰指数结果显示，马赞德兰省（Mazandaran）、吉兰省（Gilan）与加兹温省（Qazvin）这3个省份存在高死亡率聚集模式。在识别高、低风险点位时，局部盖氏指数结果显示：库姆省（Qom）、加兹温省与马赞德兰省存在3个置信区间（confidence interval）为99%的热点区域；中央省（Markazi）、德黑兰省（Tehran）、赞詹省（Zanjan）、吉兰省与戈勒斯坦省（Golestan）存在5个置信区间（confidence interval）为95%的热点区域。
**研究结论**：基于上述3个省份的事故聚集模式以及9个省份存在的热点区域，为降低伊朗行人因道路交通事故导致的死亡率，有必要明确本研究涉及省份中提升行人死亡风险的相关影响因素。因此，为降低行人死亡率，尤其是高风险省份的行人死亡率，需开展相关研究以明确行人死亡的风险因素。