云南不明原因猝死时空分布特征研究

Study on spatial-temporal distribution characteristics of Yunnan unexplained sudden death

目的掌握云南不明原因猝死时空分布特征,为病因研究提供线索。方法使用1975-2008年回顾性调查和监测报告的375例云南不明原因猝死病例,描述其时间分布特征;制作猝死自然村空间分布图、采用一阶邻近系数等空间分析方法和技术来分析病例的空间分布特征;用K-均值聚类方法将发生猝死的自然村聚成几类发病区域,分析不同区域的时间分布特征。结果云南不明原因猝死病例分布在97个自然村;猝死自然村分布在云南省中部和西北部,在空间分布上呈现聚集性特征(一阶最邻近系数为0.489,P<0.001);97.0%的猝死发生于6～9月,猝死日期中位数为7月22日,在7月和8月各出现一个高峰;按空间位置可将猝死自然村聚为4类病区,用A、B、C、D表示,以鹤庆和宁蒗为代表的B类病区发病日期中位数为7月30日,比其他病区发病日期中位数7月19日迟11天。结论云南不明原因猝死具有时间特异性和空间特异性,主要在6～9月份集中发生在云南省中部和西北部区域的山区和半山区,不同区域发病时间不完全一致。

Objective Describe the spatial-temporal characteristics of Yunnan unexplained sudden death （YUSD） for providing clues to the etiology of YUSD. Methods Descriptive method was employed to analyze the temporal distribution characteristics of 375 YUSD cases during the period 1975 - 2008, which were from report, retrospective investigation and surveillance; Spatial analysis methods and techniques, such as first-order nearest neighbor method, thematic map making, ere, were adopted to analyze the spatial distribution characteristics of these cases; K-means clustering was also used to divide YUSD Villages into some areas, and the temporal distribution characteristics of different areas were analyzed. Results Ninety-seven villages where YUSD happened were found. The affected villages are primarily located in the middle and northwest of Yunnan Province, and the spatial pattern of which is clustered （NNI = 0. 489, P 〈 0. 001 ）. 97.0% of YUSD cases were occurred during June and September, and the median date was 22nd July. YUSD villages were divided into four clusters in terms of spatial location, denoted by A, B, C and D. The median date of B cluster, 30th July, was later by eleven days than that of other affected villages, which was approximately 19th July. Conclusions YUSD has the especial characteristic of time and space, and it is mainly occurred between June and September in the semi-mountain or mountain areas of the middle and Northwest of Yunnan Province. The time of YUSD was not the same in different affected villages.